birth defect
A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...
in which there is a complete or partial absence of the
corpus callosum
The corpus callosum (Latin for "tough body"), also callosal commissure, is a wide, thick nerve tract, consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental mam ...
. It occurs when the development of the corpus callosum, the band of
white matter
White matter refers to areas of the central nervous system (CNS) that are mainly made up of myelinated axons, also called tracts. Long thought to be passive tissue, white matter affects learning and brain functions, modulating the distribution ...
brain
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...
, in the embryo is disrupted. The result of this is that the fibers that would otherwise form the corpus callosum are instead longitudinally oriented along the ipsilateral ventricular wall and form structures called Probst bundles.
In addition to agenesis, other degrees of callosal defects exist, including
hypoplasia
Hypoplasia (from Ancient Greek ὑπo- ''hypo-'' 'under' + πλάσις ''plasis'' 'formation'; adjective form ''hypoplastic'') is underdevelopment or incomplete development of a tissue or organ.dysgenesis (malformation).
ACC is found in many syndromes and can often present alongside hypoplasia of the
cerebellar vermis
The cerebellar vermis (from Latin ''vermis,'' "worm") is located in the medial, cortico-nuclear zone of the cerebellum, which is in the posterior fossa of the cranium. The primary fissure in the vermis curves ventrolaterally to the superior ...
. When this is the case, there can also be an enlarged
fourth ventricle
The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. These cavities, known collectively as the ventricular system, consist of the left and right lateral ventricles, the third ventricle, and the fourth ve ...
or
hydrocephalus
Hydrocephalus is a condition in which an accumulation of cerebrospinal fluid (CSF) occurs within the brain. This typically causes increased intracranial pressure, pressure inside the skull. Older people may have headaches, double vision, poor ...
; this is called
Dandy–Walker malformation
Dandy–Walker malformation (DWM), also known as Dandy–Walker syndrome (DWS), is a rare congenital brain malformation in which the part joining the two hemispheres of the cerebellum (the cerebellar vermis) does not fully form, and the fourth ...
.
Signs and symptoms
Signs and symptoms of ACC and other callosal disorders vary greatly among individuals. However, some characteristics common in individuals with callosal disorders include vision impairments, low muscle tone (
hypotonia
Hypotonia is a state of low muscle tone (the amount of tension or resistance to stretch in a muscle), often involving reduced muscle strength. Hypotonia is not a specific medical disorder, but a potential manifestation of many different diseases a ...
), poor
motor coordination Motor coordination is the orchestrated movement of multiple body parts as required to accomplish intended actions, like walking. This coordination is achieved by adjusting kinematic and kinetic parameters associated with each body part involved in t ...
, delays in motor milestones such as sitting and walking, delayed toilet training and
dysautonomic
Dysautonomia or autonomic dysfunction is a condition in which the autonomic nervous system (ANS) does not work properly. This may affect the functioning of the heart, bladder, intestines, sweat glands, pupils, and blood vessels. Dysautonomia has ...
symptoms such as low perception of pain or chewing and swallowing difficulties.
Laboratory research has demonstrated that individuals with ACC have difficulty transferring more complex information from one hemisphere to the other. They also have been shown to have some cognitive disabilities (difficulty in complex problem solving) and social difficulties (missing subtle social cues), even when their intelligence quotient is normal. Recent research suggests that specific social difficulties may be a result of impaired face processing. The unusual social behavior in childhood often resembles that of an
autism spectrum disorder
The autism spectrum, often referred to as just autism or in the context of a professional diagnosis autism spectrum disorder (ASD) or autism spectrum condition (ASC), is a neurodevelopmental disorder, neurodevelopmental condition (or conditions) ...
.
Other characteristics sometimes associated with callosal disorders include
seizures
An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or neural oscillation, synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much o ...
,
spasticity
Spasticity () is a feature of altered skeletal muscle performance with a combination of paralysis, increased tendon reflex activity, and hypertonia. It is also colloquially referred to as an unusual "tightness", stiffness, or "pull" of muscles.
...
, early feeding difficulties and/or gastric reflux, hearing impairments, abnormal head and facial features, and intellectual disability.
Associated brain anomalies
Brain anomalies that can sometimes occur in syndromes that cause callosal disorders include:
* Aplasia of the
cerebellar vermis
The cerebellar vermis (from Latin ''vermis,'' "worm") is located in the medial, cortico-nuclear zone of the cerebellum, which is in the posterior fossa of the cranium. The primary fissure in the vermis curves ventrolaterally to the superior ...
*
Chiari malformation
Chiari malformation (CM) is a structural defect in the cerebellum, characterized by a downward displacement of one or both cerebellar tonsils through the foramen magnum (the opening at the base of the skull). CMs can cause headaches, difficu ...
*
Colpocephaly
Colpocephaly is a cephalic disorder involving the disproportionate enlargement of the occipital horns of the lateral ventricles and is usually diagnosed early after birth due to seizures. It is a nonspecific finding and is associated with multiple ...
Holoprosencephaly
Holoprosencephaly (HPE) is a cephalic disorder in which the prosencephalon (the forebrain of the embryo) fails to develop into two hemispheres, typically occurring between the 18th and 28th day of gestation. Normally, the forebrain is formed and t ...
*
Hydrocephalus
Hydrocephalus is a condition in which an accumulation of cerebrospinal fluid (CSF) occurs within the brain. This typically causes increased intracranial pressure, pressure inside the skull. Older people may have headaches, double vision, poor ...
*
Neuronal migration disorders
Neuronal migration disorder (NMD) refers to a heterogenous group of disorders that, it is supposed, share the same etiopathological mechanism: a variable degree of disruption in the migration of neuroblasts during neurogenesis. The neuronal migrat ...
such as
grey matter heterotopia
MRI of a child experiencing seizures. There are small foci of grey matter Heterotopia (medicine)">heterotopia in the corpus callosum, deep to the Cortical dysplasia, dysplastic cortex. (double arrows)
Gray matter heterotopias are neurological d ...
*
Schizencephaly
Schizencephaly () is a rare birth defect characterized by abnormal clefts lined with grey matter that form the ependyma of the cerebral ventricles to the pia mater. These clefts can occur bilaterally or unilaterally. Common clinical features of ...
Associated syndromes and conditions
Some syndromes that frequently include ACC are:
*
Acrocallosal syndrome
Acrocallosal syndrome (also known as ACLS) is an extremely rare autosomal recessive syndrome characterized by corpus callosum agenesis, polydactyly, multiple dysmorphic features, motor and intellectual disabilities, and other symptoms. The syndrom ...
*
Aicardi syndrome
Aicardi syndrome is a rare genetic malformation syndrome characterized by the partial or complete absence of a key structure in the brain called the corpus callosum, the presence of retinal lacunes, and epileptic seizures in the form of infanti ...
Dwarfism
Dwarfism is a condition wherein an organism is exceptionally small, and mostly occurs in the animal kingdom. In humans, it is sometimes defined as an adult height of less than , regardless of sex; the average adult height among people with dw ...
*
FG syndrome
FG syndrome (FGS) is a rare genetic syndrome caused by one or more recessive genes located on the X chromosome and causing physical anomalies and developmental delays. FG syndrome was named after the first letters of the surnames of the first pat ...
*
L1CAM syndrome
L1 syndrome is a group of mild to severe X-linked recessive inheritance, X-linked recessive disorders that share a common genetic basis. The spectrum of L1 syndrome disorders includes X-linked complicated corpus callosum dysgenesis, spastic paraple ...
*
Microcephalic osteodysplastic primordial dwarfism type II
Microcephalic osteodysplastic primordial dwarfism type II (MOPD II) is a form of primordial dwarfism associated with brain and skeletal abnormalities. It was characterized in 1982.
MOPD II is listed as a rare disease by the Office of Rare Diseas ...
*
Mowat–Wilson syndrome
Mowat–Wilson syndrome is a rare genetic disorder that was clinically delineated by David R. Mowat and Meredith J. Wilson in 1998. The condition affects both males and females, has been described in various countries and ethnic groups around the w ...
*
Oculocerebrocutaneous syndrome
Oculocerebrocutaneous syndrome is a condition characterized by orbital cysts, microphthalmia, porencephaly, agenesis of the corpus callosum, and facial skin tags. Presentation
These include
* Skin lesions
** Hypoplastic or aplastic skin defects ...
*
Saal Bulas syndrome
Saal Bulas syndrome is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that Saal Bulas syndrome, or a subtype of Saal Bulas syndrome, affects fewer than 200,000 people in the US ...
*
Septo-optic dysplasia
Septo-optic dysplasia (SOD), known also as de Morsier syndrome, is a rare congenital malformation syndrome that features a combination of the underdevelopment of the optic nerve, pituitary gland dysfunction, and absence of the septum pellucidum (a ...
(
optic nerve hypoplasia
Optic nerve hypoplasia (ONH) is a medical condition arising from the underdevelopment of the optic nerve(s). This condition is the most common congenital optic nerve anomaly. The optic disc appears abnormally small, because not all the optic nerve ...
)
*
Shapiro syndrome
Shapiro syndrome is an extremely rare disorder consisting of paroxysmal hypothermia (due to hypothalamic dysfunction of thermoregulation), hyperhydrosis (sweating), and agenesis of the corpus callosum with onset typically on adulthood. The disease ...
* Vici syndrome
Some conditions that can sometimes be associated with ACC or other callosal disorders include:
*
1p36 deletion syndrome
1p36 deletion syndrome is a congenital genetic disorder characterized by moderate to severe intellectual disability, delayed growth, hypotonia, seizures, limited speech ability, malformations, hearing and vision impairment, and distinct facial fe ...
*
13q deletion syndrome
13q deletion syndrome is a rare genetic disease caused by the deletion of some or all of the large arm of human chromosome 13. Depending upon the size and location of the deletion on chromosome 13, the physical and mental manifestations will vary. ...
*
CDK13-related disorder
CDK13-related disorder, also known as congenital heart defects, dysmorphic facial features and intellectual developmental disorder (CHDFIDD), is a very rare autosomal dominant genetic condition characterised by congenital heart defects, intel ...
*
Craniofacial abnormalities
Craniofacial abnormalities are congenital musculoskeletal disorders which primarily affect the cranium and facial bones.
They are associated with the development of the pharyngeal arches. Approximately, 5% of the UK or USA population present wit ...
Fetal warfarin syndrome
Fetal warfarin syndrome is a Birth defect, disorder of the embryo which occurs in a child whose mother took the medication warfarin (brand name: Coumadin) during pregnancy. Resulting abnormalities include low birth weight, Failure to thrive, slower ...
*
Genitopatellar syndrome
Genitopatellar syndrome is a rare disorder consisting of congenital flexion contractures of the lower extremities, abnormal or missing patellae, and urogenital anomalies. Additional symptoms include microcephaly, severe psychomotor disability.
I ...
Joubert syndrome
Joubert syndrome is a rare autosomal recessive genetic disorder that affects the cerebellum, an area of the brain that controls balance and coordination.
Joubert syndrome is one of the many genetic syndromes associated with syndromic retinitis pig ...
*
Lujan–Fryns syndrome
Lujan–Fryns syndrome (LFS) is an X-linked genetic disorder that causes mild to moderate intellectual disability and features described as Marfanoid habitus, referring to a group of physical characteristics similar to those found in Marfan syndrom ...
*
Marden–Walker syndrome
Marden–Walker syndrome (MWS) is a rare autosomal recessive congenital disorder. It is characterized by blepharophimosis, microcephaly, micrognathia, multiple joint contractures, arachnodactyly, camptodactyly, kyphoscoliosis and delayed motor de ...
infections
An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmiss ...
*
Metabolic disorders
A metabolic disorder is a disorder that negatively alters the body's processing and distribution of macronutrients, such as Protein, proteins, Fat, fats, and Carbohydrate, carbohydrates. Metabolic disorders can happen when abnormal chemical react ...
*
Okamoto syndrome
Okamoto syndrome (OS), also known as Au–Kline syndrome (AKS), is a very rare autosomal dominant genetic condition characterised by congenital hydronephrosis, low muscle tone, heart defects, intellectual disability and characteristic facial f ...
*
Opitz G/BBB syndrome
Opitz G/BBB syndrome, also known as Opitz syndrome, G syndrome or BBB syndrome, is a rare genetic disorder that will affect physical structures along the midline of the body. The letters G and BBB represent the last names of the families that were ...
Pitt–Hopkins syndrome
Pitt–Hopkins syndrome (PTHS) is a rare genetic disorder characterized by developmental delay, epilepsy, distinctive facial features, and possible intermittent hyperventilation followed by apnea. Pitt-Hopkins syndrome can be marked by intellectu ...
*
Sensenbrenner syndrome
Sensenbrenner syndrome (OMIM #218330) is a rare (less than 20 cases reported by 2010) multisystem disease first described by Judith A. Sensenbrenner in 1975. It is inherited in an autosomal recessive fashion, and a number of genes appear to be resp ...
*
Strømme syndrome
Strømme syndrome is a very rare autosomal recessive genetic condition characterised by intestinal atresia (in which part of the intestine is missing), eye abnormalities and microcephaly. The intestinal atresia is of the "apple-peel" type ...
*
Triploid syndrome
Triploid syndrome, also called triploidy, is a chromosomal disorder in which a fetus has three copies of every chromosome instead of the normal two. If this occurs in only some cells, it is called mosaic triploidy and is less severe.
Most embryo ...
*
Trisomy 9
Full trisomy 9 is a lethal chromosomal disorder caused by having three copies (trisomy) of chromosome number 9. It can be a viable condition if trisomy affects only part of the cells of the body (mosaicism) or in cases of partial trisomy (triso ...
Agenesis of the corpus callosum is caused by disruption to development of the fetal brain between the 3rd and 12th weeks of pregnancy. In most cases, it is not possible to know what caused an individual to have ACC or another callosal disorder. However, research suggests that some possible causes may include chromosome errors, inherited genetic factors, prenatal infections or injuries, prenatal toxic exposures, structural blockage by cysts or other brain abnormalities and metabolic disorders.
Ciliopathies: rare genetic disorders
Until recently, the medical literature did not indicate a connection among many
genetic disorder
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders ...
s, both
genetic syndrome
A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek σύνδρομον, meaning "concurrence". When a syndrome is paired ...
s and genetic diseases, that are now being found to be related. As a result of new genetic research, some of these are, in fact, highly related in their
root cause Root cause may refer to:
* "Root Cause" (''Person of Interest''), a TV show episode
* Root cause analysis
In science
Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predic ...
despite the widely varying
symptoms
Signs and symptoms are the observed or detectable signs, and experienced symptoms of an disease, illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormali ...
apparent on clinical examination. Agenesis of the corpus callosum is one such disease, part of an emerging class of diseases called ciliopathies. The underlying cause may be a dysfunctional molecular mechanism in the primary
cilia
The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projecti ...
structures of the
cell
Cell most often refers to:
* Cell (biology), the functional basic unit of life
Cell may also refer to:
Locations
* Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...
organelle
In cell biology, an organelle is a specialized subunit, usually within a cell, that has a specific function. The name ''organelle'' comes from the idea that these structures are parts of cells, as organs are to the body, hence ''organelle,'' the ...
s that are present in many cellular types throughout the
human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
body. The cilia defects adversely affect "numerous critical developmental signaling pathways" essential to cellular development and thus offer a plausible hypothesis for the often multi-symptom nature of a large set of syndromes and diseases. Known ciliopathies include
primary ciliary dyskinesia
Primary ciliary dyskinesia (PCD) is a rare, autosomal recessive genetic ciliopathy, that causes defects in the action of cilia lining the upper and lower respiratory tract, sinuses, Eustachian tube, middle ear, Fallopian tube, and flagella of ...
,
Bardet–Biedl syndrome
Bardet–Biedl syndrome (BBS) is a ciliopathic human genetic disorder that produces many effects and affects many body systems. It is characterized by rod/cone dystrophy, polydactyly, central obesity, hypogonadism, and kidney dysfunction in som ...
,
polycystic kidney
Polycystic kidney disease (PKD or PCKD, also known as polycystic kidney syndrome) is a genetic disorder in which the renal tubules become structurally abnormal, resulting in the development and growth of multiple cysts within the kidney. These cy ...
and
liver disease
Liver disease, or hepatic disease, is any of many diseases of the liver. If long-lasting it is termed chronic liver disease. Although the diseases differ in detail, liver diseases often have features in common.
Signs and symptoms
Some of the sig ...
,
nephronophthisis
Nephronophthisis is a genetic disorder of the kidneys which affects children. It is classified as a medullary cystic kidney disease. The disorder is inherited in an autosomal recessive fashion and, although rare, is the most common genetic cause o ...
,
Alström syndrome
Alström syndrome (AS), also called Alström–Hallgren syndrome, is a very rare autosomal recessive genetic disorder characterised by childhood obesity and multiple organ dysfunction. Symptoms include early-onset type 2 diabetes, cone-rod dystr ...
,
Meckel–Gruber syndrome
Meckel-Gruber syndrome is a rare, lethal ciliopathic genetic disorder, characterized by renal cystic dysplasia, central nervous system malformations (occipital encephalocele), polydactyly (postaxial), hepatic developmental defects, and pulmonary ...
In utero
''In Utero'' is the third and final studio album by American rock band Nirvana. It was released on September 21, 1993, by DGC Records. After breaking into the mainstream with their second album, ''Nevermind'' (1991), Nirvana hired Steve Albini t ...
exposure to
cocaine
Cocaine (from , from , ultimately from Quechuan languages, Quechua: ''kúka'') is a central nervous system (CNS) stimulant mainly recreational drug use, used recreationally for its euphoria, euphoric effects. It is primarily obtained from t ...
,
heroin
Heroin, also known as diacetylmorphine and diamorphine among other names, is a potent opioid mainly used as a recreational drug for its euphoric effects. Medical grade diamorphine is used as a pure hydrochloride salt. Various white and brow ...
,
amphetamines
Substituted amphetamines are a class of compounds based upon the amphetamine structure; it includes all derivative compounds which are formed by replacing, or substituting, one or more hydrogen atoms in the amphetamine core structure with sub ...
and
phenylpropanolamine
Phenylpropanolamine (PPA) is a sympathomimetic agent which is used as a decongestant and appetite suppressant. It was commonly used in prescription and over-the-counter cough and cold preparations. In veterinary medicine, it is used to contro ...
can lead to agenesis of corpus callosum.
Diagnosis
Callosal disorders can be diagnosed through brain imaging studies or during autopsy. They may be diagnosed through an
MRI
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...
,
CT scan
A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...
,
Sonography
Medical ultrasound includes diagnostic techniques (mainly medical imaging, imaging techniques) using ultrasound, as well as therapeutic ultrasound, therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal ...
,
prenatal ultrasound
Obstetric ultrasonography, or prenatal ultrasound, is the use of medical ultrasonography in pregnancy, in which sound waves are used to create real-time visual images of the developing embryo or fetus in the uterus (womb). The procedure is a stan ...
, or prenatal MRI.
Treatment
There are currently no specific medical treatments for callosal disorders, but individuals with ACC and other callosal disorders may benefit from a range of developmental therapies, educational support, and services. It is important to consult with a variety of medical, health, educational, and social work professionals. Such professionals include
neurologists
Neurology (from el, νεῦρον (neûron), "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the brain, the spinal ...
,
neuropsychologists
Neuropsychology is a branch of psychology concerned with how a person's cognition and behavior are related to the brain and the rest of the nervous system. Professionals in this branch of psychology often focus on how injuries or illnesses of ...
,
occupational therapists
Occupational therapists (OTs) are health care professionals specializing in occupational therapy and occupational science. OTs and occupational therapy assistants (OTAs) use scientific bases and a holistic perspective to promote a person's abilit ...
,
physical therapists
Physical therapy (PT), also known as physiotherapy, is one of the allied health professions. It is provided by physical therapists who promote, maintain, or restore health through physical examination, diagnosis, management, prognosis, patient ...
,
speech and language pathologists
Speech is a human vocal communication using language. Each language uses phonetic combinations of vowel and consonant sounds that form the sound of its words (that is, all English words sound different from all French words, even if they are th ...
,
pediatricians
Pediatrics ( also spelled ''paediatrics'' or ''pædiatrics'') is the branch of medicine that involves the medical care of infants, children, adolescents, and young adults. In the United Kingdom, paediatrics covers many of their youth until the ...
, recreation therapists,
music therapist
Music therapy, an allied health profession, "is the clinical and evidence-based use of music interventions to accomplish individualized goals within a therapeutic relationship by a credentialed professional who has completed an approved music th ...
s,
geneticist
A geneticist is a biologist or physician who studies genetics, the science of genes, heredity, and variation of organisms. A geneticist can be employed as a scientist or a lecturer. Geneticists may perform general research on genetic processe ...
s,
social worker
Social work is an academic discipline and practice-based profession concerned with meeting the basic needs of individuals, families, groups, communities, and society as a whole to enhance their individual and collective well-being. Social work ...
s,
special educators
Special education (known as special-needs education, aided education, exceptional education, alternative provision, exceptional student education, special ed., SDC, or SPED) is the practice of educating students in a way that accommodates th ...
caregiver
A caregiver or carer is a paid or unpaid member of a person's social network who helps them with activities of daily living. Since they have no specific professional training, they are often described as informal caregivers. Caregivers most commo ...
s for adults.
Prognosis
Prognosis
Prognosis (Greek: πρόγνωσις "fore-knowing, foreseeing") is a medical term for predicting the likely or expected development of a disease, including whether the signs and symptoms will improve or worsen (and how quickly) or remain stabl ...
varies depending on the type of callosal abnormality and associated conditions or syndromes. It is not possible for the corpus callosum to regenerate. Neuropsychological testing reveals subtle differences in higher cortical function compared to individuals of the same age and education without ACC,
although some individuals with callosal disorders have average intelligence and live normal lives.
Culture
Kim Peek
Laurence Kim Peek (November 11, 1951December 19, 2009) was an People of the United States, American savant syndrome, savant. Known as a "megasavant", he had an exceptional memory, but he also experienced social difficulties, possibly resulting fr ...
, inspiration for the film ''
Rain Man
''Rain Man'' is a 1988 American road movie, road Drama (film and television), drama film directed by Barry Levinson and written by Barry Morrow and Ronald Bass. It tells the story of abrasive, selfish young wikt:wheeler-dealer, wheeler-dealer C ...
'' and renowned for his
savant
Savant syndrome () is a rare condition in which someone with significant mental disabilities demonstrates certain abilities far in excess of average. The skills that savants excel at are generally related to memory. This may include rapid calcu ...
abilities, was born with agenesis of the corpus callosum, along with
macrocephaly
Macrocephaly is a condition in which circumference of the human head is abnormally large. It may be pathological or harmless, and can be a familial genetic characteristic. People diagnosed with macrocephaly will receive further medical tests to ...
and damage to the
cerebellum
The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebel ...