Following is true about Turners syndrome except-
External genitilia are normal
Biscuspid aortic valve
Swelling of nape of neck
Short stature
Ans. is 'a" i.e., External genitalia are normal Turners syndromeo Turner's syndrome is the most common sex chromosomal disorder in phenotypic females.o Turner's syndrome results from complete or partial loss of one X chromosome (45, X) and is characterised by hypogonadism in phenotypic femalesFeatures of Turner syndrome in childreno The most severely affected patients generally present during infancy with edema (owing to lymph stasis) of the dorsum of the hand and foot and sometimes swelling of the nape of the neck.o Swelling of the neck is related to markedly distended lymphatic channels, producing so called cystic hygroma.o As these infants develop, the swelling subsides but often leave bilateral neck webbing and persistent looseness of skin on the back of the neck.o Congenital heart disease is also common, particularly preducta! coarctation of Aorta and bicuspid Aortic valve,o C.V.S abnormalities are most important cause of mortality in children with Turners syndrome.Features of Turner's syndrome in Adolescents and Adulto Is failure to develop normal secondary sex characteristics.o The genitalia remains infantile, breast development is inadequate and there is little pubic hair,o Nipples are widely spaced.o Turner syndrome is the single most important cause of primary amenorrhoea accounting for approximately '6 of the cases.o Short stature (height rarely exceeds 150 cm ).o The mental status is usually normal but subtle defects in nonverbal, visual spatial information processing have been noted (mental retardation is associated with the presence of extra chromosome not with loss of X chromosome).o Autoantibodies directed to the thyroid gland and upto one half of these patients develop hypothyroidism.o Low posterior hairline, webbing of neck, cubitus valgus, streak ovaries.o Glucose intolerance, obesity and insulin resistance are also seen.
Mendelian Disorders: Single-Gene Defects