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XYYYY Syndrome
XYYYY syndrome, also known as 49,XYYYY, is an exceptionally rare chromosomal disorder in which a male has three additional copies of the Y chromosome. Only seven non-mosaic cases of the disorder have ever been recorded in the medical literature, as well as five mosaic cases, of which two had more 48,XYYY than 49,XYYYY cells. Due to the extreme rarity of the disorder, little is understood about it, and the phenotype appears to be variable. Phenotype XYYYY syndrome is associated with developmental and skeletal anomalies that are also observed in other sex chromosome aneuploidies. Findings associated with the karyotype include hypertelorism (wide-spaced eyes), low-set ears, radioulnar synostosis (fusion of the long bones in the forearm), and clinodactyly (incurved pinky fingers). Intellectual disability has been observed in all cases old enough to test and is in the mild to moderate range. Though other Y-chromosome polysomy disorders are associated with tall stature, this does not a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosomal Disorder
A chromosomal abnormality, chromosomal anomaly, chromosomal aberration, chromosomal mutation, or chromosomal disorder, is a missing, extra, or irregular portion of chromosomal DNA. These can occur in the form of numerical abnormalities, where there is an atypical number of chromosomes, or as structural abnormalities, where one or more individual chromosomes are altered. Chromosome mutation was formerly used in a strict sense to mean a change in a chromosomal segment, involving more than one gene. Chromosome anomalies usually occur when there is an error in cell division following meiosis or mitosis. Chromosome abnormalities may be detected or confirmed by comparing an individual's karyotype, or full set of chromosomes, to a typical karyotype for the species via genetic testing. Numerical abnormality An abnormal number of chromosomes is called aneuploidy, and occurs when an individual is either missing a chromosome from a pair (resulting in monosomy) or has more than two chromosome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intellectual Disability
Intellectual disability (ID), also known as general learning disability in the United Kingdom and formerly mental retardation,Rosa's Law, Pub. L. 111-256124 Stat. 2643(2010). is a generalized neurodevelopmental disorder characterized by significantly impaired intellectual and adaptive functioning. It is defined by an IQ under 70, in addition to deficits in two or more adaptive behaviors that affect everyday, general living. Intellectual functions are defined under DSM-V as reasoning, problem‑solving, planning, abstract thinking, judgment, academic learning, and learning from instruction and experience, and practical understanding confirmed by both clinical assessment and standardized tests. Adaptive behavior is defined in terms of conceptual, social, and practical skills involving tasks performed by people in their everyday lives. Intellectual disability is subdivided into syndromic intellectual disability, in which intellectual deficits associated with other medical and be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Chromosome Aneuploidies
Sex is the trait that determines whether a sexually reproducing animal or plant produces male or female gametes. Male plants and animals produce smaller mobile gametes (spermatozoa, sperm, pollen), while females produce larger ones (ova, often called egg cells). Organisms that produce both types of gametes are called hermaphrodites. During sexual reproduction, male and female gametes fuse to form zygotes, which develop into offspring that inherit traits from each parent. Males and females of a species may have physical similarities (sexual monomorphism) or differences (sexual dimorphism) that reflect various reproductive pressures on the respective sexes. Mate choice and sexual selection can accelerate the evolution of physical differences between the sexes. The terms ''male'' and ''female'' typically do not apply in sexually undifferentiated species in which the individuals are isomorphic (look the same) and the gametes are isogamous (indistinguishable in size and shape), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XYYY Syndrome
XYYY syndrome, also known as 48,XYYY, is a chromosomal disorder in which a male has two extra copies of the Y chromosome. The syndrome is exceptionally rare, with only twelve recorded cases. The presentation of the syndrome is heterogeneous, but appears to be more severe than its counterpart XYY syndrome. Common traits include borderline to mild intellectual disability, infertility, radioulnar synostosis (the fusion of the long bones in the forearm), and in some cases tall stature. Presentation The presentation of XYYY syndrome is variable and at this time not entirely clear. As all known cases were diagnosed postnatally (after birth), and the similar XYY syndrome is known to have a milder phenotype in prenatally than postnatally diagnosed cases, it is suspected that many cases of XYYY syndrome may be mild or asymptomatic. The intellectual abilities of known XYYY cases have varied, especially in cases with mosaicism, but in most cases are in the borderline intellectual functi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XYY Syndrome
XYY syndrome, also known as Jacobs syndrome, is an aneuploid genetic condition in which a male has an extra Y chromosome. There are usually few symptoms. These may include being taller than average, acne, and an increased risk of learning disabilities. The person is generally otherwise normal, including typical rates of fertility. The condition is generally not inherited from a person's parents but rather occurs as a result of a random event during sperm development. Diagnosis is by a chromosomal analysis, but most of those affected are not diagnosed within their lifetime. There are 47 chromosomes, instead of the usual 46, giving a 47,XYY karyotype. Treatment may include speech therapy or extra help with schoolwork, but outcomes are generally good. The condition occurs in about 1 in 1,000 male births. Many people with the condition are unaware that they have it. The condition was first described in 1961. Signs and symptoms Physical traits People with the 47,XYY karyotyp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
45,X0
Turner syndrome (TS), also known as 45,X, or 45,X0, is a genetic condition in which a female is partially or completely missing an X chromosome. Signs and symptoms vary among those affected. Often, a short and webbed neck, low-set ears, low hairline at the back of the neck, short stature, and swollen hands and feet are seen at birth. Typically, those affected do not develop menstrual periods, or breasts without hormone treatment and are unable to have children without reproductive technology. Heart defects, diabetes, and low thyroid hormone occur in the disorder more frequently than average. Most people with Turner syndrome have normal intelligence; however, many have problems with spatial visualization that may be needed in order to learn mathematics. Vision and hearing problems also occur more often than average. Turner syndrome is not usually inherited; rather, it occurs during formation of the reproductive cells in a parent or in early cell division during development. N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azoospermia
Azoospermia is the medical condition of a man whose semen contains no sperm. It is associated with male infertility, but many forms are amenable to medical treatment. In humans, azoospermia affects about 1% of the male population and may be seen in up to 20% of male infertility situations in Canada. In a non-pathological context, azoospermia is also the intended result of a successful vasectomy. Classification Azoospermia can be classified into three major types as listed. Many conditions listed may also cause various degrees of oligospermia rather than azoospermia. Pretesticular and testicular azoospermia are known as non-obstructive azoospermia, whereas post-testicular azoospermia is considered obstructive. Pretesticular Pretesticular azoospermia is characterized by inadequate stimulation of otherwise normal testicles and genital tract. Typically, follicle-stimulating hormone (FSH) levels are low (hypogonadotropic) commensurate with inadequate stimulation of the testes to prod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
