A chromosomal defect in women with a 45,x karyotype (45 chromosomes rather than 46). Clinical features include short stature, webbed neck, abnormal ovarian development, infertility, specific social and cognitive deficits such as nonverbal learning disabilities, and sometimes intellectual disability.
A genetic abnormality affecting females in which one of the sex-determining pair of chromosomes is missing, leaving a total of 45 rather than 46 chromosomes. Symptoms of include incomplete development of the ovaries, short stature, and webbing of the neck.
A congenital condition in females, caused by the absence of one of the pair of X chromosomes, in which sexual development is retarded and no ovaries develop [Described 1938. After Henry Hubert Turner (b. 1892), US endocrinologist, Clinical professor of Medicine, Oklahoma University, USA.]
Turner syndrome is a noninherited, genetic disorder found in females that is caused by the complete absence (classic karyotype) or abnormal presentation (mosaicism) of the second X chromosome. Turner syndrome can also occur when there is structural abnormality or rearrangement of one or both of the X chromosomes.
A congenital condition resulting from a chromosomal abnormality, in which a female has not the normal two sex chromosomes (XX) but only one. For people with Turner’s syndrome, sexual development and menstruation come late, if at all. Though with hormone treatment they may develop secondary sex characteristics, they are unable to bear children. People with Turner’s syndrome are generally short, are likely to have ear and hearing problems and heart problems, and have a characteristic webbing of the neck’s skin. They sometimes have problems with spatial orientation, often leading to learning disabilities in mathematics, but have strength in verbal areas; some have mental retardation. Some females (and also some males) with apparently normal sex chromosomes have the characteristics of Turner’s syndrome; their condition is called Noonan’s syndrome.
Chromosomal abnormality in females in which there is only one X chromosome (instead of the normal two); it is characterized by dwarfism, cardiac abnormalities, underdeveloped reproductive organs, and often varying degrees of mental retardation or learning problems. Treatment is by hormone therapy and surgical correction of cardiovascular or skeletal abnormalities.
A chromosomal anomaly occurring in approximately 1 in 3,000 births due to the absence of one X chromosome; characterized by webbing of neck skin, cardiovascular abnormalities, ovarian failure, shield-shaped chest, and underdevelopment of breast, uterus, and vagina.
A chromosomal abnormality characterized by short stature and infertility in females. In Turner syndrome the ovaries fail to develop, resulting in estrogen deficiency, which prevents development of secondary sexual characteristics, such as the breasts.
A genetic defect in women in which there is only one X chromosome instead of the usual two. Affected women are infertile: they have female external genitalia but no ovaries and therefore no menstrual periods. Characteristically they are short, mentally retarded, and have a webbed neck; other developmental defects are common.
This occurs in one in 2,500 live female births. It is caused by either the absence of or an abnormality in one of the two X chromosomes. Classical Turner’s syndrome is a complete deletion of one X so that the genotype is 45XO. Half of the people with Turner’s syndrome have mosaicism with a mixture of Turner cells and normal cells, or other abnormalities of the X chromosome such as partial deletions or a ring X. They are females, both in appearance and sexually; clinical features are variable and include short stature, with final height between 1-295 m and 1-575 m, and ovarian failure. Other clinical features may include a short neck, webbing of the neck, increased carrying angle at the elbow (cubitus valgus), widely spaced nipples, cardiovascular abnormalities (of which the commonest is coarctation of the aorta [about 10 per cent]), morphological abnormalities of the kidneys (including horseshoe kidney and abnormalities of the pelviureteric tracts), recurrent otitis media, squints, increased incidence of pigmented naevi, hypothyroidism and diabetes mellitus. Intelligence is across the normal range, although there are specific learning defects which are related to hand-eye coordination and spatial awareness.