|
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 dwarfism is , although some individuals with dwarfism are slightly taller. ''Disproportionate dwarfism'' is characterized by either short limbs or a short torso. In cases of ''proportionate dwarfism'', both the limbs and torso are unusually small. Intelligence is usually normal, and most have a nearly normal life expectancy. People with dwarfism can usually bear children, though there are additional risks to the mother and child dependent upon the underlying condition. The most common and recognisable form of dwarfism in humans (comprising 70% of cases) is achondroplasia, a genetic disorder whereby the limbs are diminutive. Growth hormone deficiency is responsible for most other cases. Treatment depends on the underlying cause. Those w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 dwarfism is , although some individuals with dwarfism are slightly taller. ''Disproportionate dwarfism'' is characterized by either short limbs or a short torso. In cases of ''proportionate dwarfism'', both the limbs and torso are unusually small. Intelligence is usually normal, and most have a nearly normal life expectancy. People with dwarfism can usually bear children, though there are additional risks to the mother and child dependent upon the underlying condition. The most common and recognisable form of dwarfism in humans (comprising 70% of cases) is achondroplasia, a genetic disorder whereby the limbs are diminutive. Growth hormone deficiency is responsible for most other cases. Treatment depends on the underlying cause. Those w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achondroplasia
Achondroplasia is a genetic disorder with an autosomal dominant pattern of inheritance whose primary feature is dwarfism. In those with the condition, the arms and legs are short, while the torso is typically of normal length. Those affected have an average adult height of for males and for females. Other features can include an enlarged head and prominent forehead. Complications can include sleep apnea or recurrent ear infections. Achondroplasia includes short-limb skeletal dysplasia with severe combined immunodeficiency. Achondroplasia is caused by a mutation in the fibroblast growth factor receptor 3 (''FGFR3'') gene that results in its protein being overactive. Achondroplasia results in impaired endochondral bone growth (bone growth within cartilage). The disorder has an autosomal dominant mode of inheritance, meaning only one mutated copy of the gene is required for the condition to occur. About 80% of cases occur in children of parents of average stature and result f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achondroplasia
Achondroplasia is a genetic disorder with an autosomal dominant pattern of inheritance whose primary feature is dwarfism. In those with the condition, the arms and legs are short, while the torso is typically of normal length. Those affected have an average adult height of for males and for females. Other features can include an enlarged head and prominent forehead. Complications can include sleep apnea or recurrent ear infections. Achondroplasia includes short-limb skeletal dysplasia with severe combined immunodeficiency. Achondroplasia is caused by a mutation in the fibroblast growth factor receptor 3 (''FGFR3'') gene that results in its protein being overactive. Achondroplasia results in impaired endochondral bone growth (bone growth within cartilage). The disorder has an autosomal dominant mode of inheritance, meaning only one mutated copy of the gene is required for the condition to occur. About 80% of cases occur in children of parents of average stature and result f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midget
Midget (from ''midge'', a tiny biting insect) is a term for a person of unusually short stature that is considered by some to be pejorative due to its etymology. While not a medical term like "dwarfism", a medical condition with a number of causes including achondroplasia, there is overlap, particularly in proportionate dwarfism. The word has a history of association with the performance arts as little people were often employed by acts in the circus, professional wrestling and vaudeville. The term may also refer to anything of much smaller than normal size, as a synonym for "miniature" or "mini", such as midget cell, midget crabapple, midget flowerpecker, midget submarine, MG Midget, Daihatsu Midget, and the Midget Mustang airplane; or to anything that regularly uses anything that is smaller than normal (other than a person), such as midget car racing and quarter midget racing. "Midget" may also reference a smaller version of play or participation, such as midget golf; or t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteochondrodysplasia
Osteochondrodysplasia is a general term for a disorder of the development (dysplasia) of bone ("osteo") and cartilage ("chondro"). Osteochondrodysplasias are rare diseases. About 1 in 5,000 babies are born with some type of skeletal dysplasia. Nonetheless, if taken collectively, genetic skeletal dysplasias or osteochondrodysplasias comprise a recognizable group of genetically determined disorders with generalized skeletal affection. Osteochondrodysplasias can result in marked functional limitation and even mortality. Osteochondrodysplasias subtypes can overlap in clinical aspects, therefore plain radiography is absolutely necessary to establish an accurate diagnosis. Magnetic resonance imaging can provide further diagnostic insights and guide treatment strategies especially in cases of spinal involvement. Early diagnosis, and timely management of skeletal dysplasia are important to combat functional deterioration. Types Achondroplasia ''Achondroplasia'' is a type of autosomal d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypochondroplasia
Hypochondroplasia (HCH) is a developmental disorder caused by an autosomal dominant genetic defect in the fibroblast growth factor receptor 3 gene (''FGFR3'') that results in a disproportionately short stature, micromeliaupdate 2013 and a head that appears large in comparison with the underdeveloped portions of the body. It is classified as short-limbed dwarfism. Signs and symptoms Individuals affected by this disorder appear normal at birth. As the infant grows, however, their arms and legs do not develop properly, and their body becomes thicker and shorter than normal. The following are characteristics consistent with this condition: * Brachydactyly * Short stature * Micromelia * Skeletal dysplasia * Abnormality of femur Cause Hypochondroplasia is transmitted as an autosomal dominant trait affecting the ''FGFR3'' gene on chromosome 4p16.3. There is currently no cure for this condition. Pathophysiology This disorder results from mutations in the proximal tyrosine kinase domain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Growth Hormone Deficiency
Growth hormone deficiency (GHD), or human growth hormone deficiency, is a medical condition resulting from not enough growth hormone (GH). Generally the most noticeable symptom is that an individual attains a short height. Newborns may also present low blood sugar or a small penis size. In adults there may be decreased muscle mass, high cholesterol levels, or poor bone density. GHD can be present at birth or develop later in life. Causes may include genetics, trauma, infections, tumors, or radiation therapy. Genes that may be involved include GH1, GHRHR, or BTK. In a third of cases no cause is apparent. The underlying mechanism generally involves problems with the pituitary gland. Some cases are associated with a lack of other pituitary hormones, in which case it is known as combined pituitary hormone deficiency. Diagnosis involves blood tests to measure growth hormone levels. Treatment is by growth hormone replacement using synthetic human growth hormone. The frequency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Growth Hormone Deficiency
Growth hormone deficiency (GHD), or human growth hormone deficiency, is a medical condition resulting from not enough growth hormone (GH). Generally the most noticeable symptom is that an individual attains a short height. Newborns may also present low blood sugar or a small penis size. In adults there may be decreased muscle mass, high cholesterol levels, or poor bone density. GHD can be present at birth or develop later in life. Causes may include genetics, trauma, infections, tumors, or radiation therapy. Genes that may be involved include GH1, GHRHR, or BTK. In a third of cases no cause is apparent. The underlying mechanism generally involves problems with the pituitary gland. Some cases are associated with a lack of other pituitary hormones, in which case it is known as combined pituitary hormone deficiency. Diagnosis involves blood tests to measure growth hormone levels. Treatment is by growth hormone replacement using synthetic human growth hormone. The frequency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hormone Disorders
Endocrine diseases are disorders of the endocrine system. The branch of medicine associated with endocrine disorders is known as endocrinology. Types of disease Broadly speaking, endocrine disorders may be subdivided into three groups: # Endocrine gland hypofunction/hypo secretion (leading to hormone deficiency) # Endocrine gland hyperfunction/hypersecretion (leading to hormone excess) # Tumours (benign or malignant) of endocrine glands Endocrine disorders are often quite complex, involving a mixed picture of hyposecretion and hypersecretion because of the feedback mechanisms involved in the endocrine system. For example, most forms of hyperthyroidism are associated with an excess of thyroid hormone and a low level of thyroid stimulating hormone. List of diseases Glucose homeostasis disorders * Diabetes ** Type 1 Diabetes ** Type 2 Diabetes ** Gestational Diabetes ** Mature Onset Diabetes of the Young * Hypoglycemia ** Idiopathic hypoglycemia ** Insulinoma * Glucagonoma T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 are the most common, the term is mostly used when discussing disorders with a single genetic cause, either in a gene or chromosome. The mutation responsible can occur spontaneously before embryonic development (a ''de novo'' mutation), or it can be Heredity, inherited from two parents who are carriers of a faulty gene (autosomal recessive inheritance) or from a parent with the disorder (autosomal dominant inheritance). When the genetic disorder is inherited from one or both parents, it is also classified as a hereditary disease. Some disorders are caused by a mutation on the X chromosome and have X-linked inheritance. Very few disorders are inherited on the Y linkage, Y chromosome or Mitochondrial disease#Causes, mitochondrial DNA (due to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizomelia
Rhizomelia refers to either a disproportion of the length of the proximal limb, such as the shortened limbs of achondroplasia, or some other disorder of the hip or shoulder. According to Stedman's medical dictionary "rhizomelic" means "relating to hip or shoulder joints", while "micromelic" means "having disproportionately short or small limbs". Genetic skeletal dysplasias or Osteochondrodysplasia frequently lead to short stature, occasionally termed dwarfism, which is classified into proportionate and disproportionate short stature. Disproportionate short stature is further classified short-limb short stature and short-trunk short stature. In turn, short-limb short stature is classified into a) Rhizomelic, b) mesomelic and c) acromelic short stature. Rhizomelic short stature refers to skeletal dysplasias where the main shortening is due to involvement of the proximal limb segments i.e. femora and humeri. Typical examples of Rhizomelic short stature are achondroplasia and pseudoacho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short Stature
Short stature refers to a height of a human which is below typical. Whether a person is considered short depends on the context. Because of the lack of preciseness, there is often disagreement about the degree of shortness that should be called ''short''. Dwarfism is the condition of being very short, often caused by a medical condition. In a medical context, short stature is typically defined as an adult height that is more than two standard deviations below a population’s mean for age and gender, which corresponds to the shortest 2.3% of individuals in that population. The median or typical adult height in developed countries is about for men and for women. Causes Shortness in children and young adults nearly always results from below-average growth in childhood, while shortness in older adults usually results from loss of height due to kyphosis of the spine or collapsed vertebrae from osteoporosis. The most common causes of short stature in childhood are constitutional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
