Question
Question: A man with enlarged breasts, sparse body hair and XXY chromosome complement is suffering from A. D...
A man with enlarged breasts, sparse body hair and XXY chromosome complement is suffering from
A. Down’s syndrome
B. Turner’s syndrome
C. Klinefelter’s syndrome
D. Super female
Solution
Some of the signs of these syndromes are similar to female characteristics.
Complete step by step answer:
It is caused due to the presence of an extra ‘X’ chromosome in males resulting in 47, XXY karyotype. The frequency of occurrence is 1:500 to 1:1000 males. It occurs due to a random genetic error after conception and is not inherited.
It affects physical and intellectual development. The symptoms include reduced facial hair, reduced body hair, breast development (Gynaecomastia), osteoporosis, small testes, problems with coordination, infertility etc. In some cases these features are too mild to be diagnosed. The extra X chromosome is responsible for the signs of Klinefelter syndrome.
Hence, the correct option is Option C, Klineflter’s syndrome.
About 10% of the individuals with this syndrome have the mosaic form i.e. the extra X chromosome is present only in some cells. The resulting karyotype is 46, XY/ 47, XXY. They have milder symptoms, depending on the amount of cells with the extra chromosome.
The addition of the extra chromosome occurs during the formation of reproductive cells. Either the egg or the sperm which forms the zygote carries the extra X chromosome. The egg or the sperm ends up with an extra X chromosome due to the nondisjunction which prevents the X chromosome from being distributed normally in the reproductive cells. The extra copy in any one of the (egg/sperm) can cause Klinefelter’s syndrome.
For diagnosis, hormone testing is done in urine and blood samples to check abnormal hormonal levels relating to the syndrome. Karyotyping is done by taking the blood sample to confirm the diagnosis. In some males, the syndrome can be diagnosed in pregnancy with the help of amniotic fluid.
For treatment, hormonal treatment is given such as testosterone replacement therapy to stimulate changes in the physical features. Other treatments and help include breast tissue removal, educational support, counselling etc.
Note:
There are variants of Klinefelter syndrome like 48, XXXY, 48, XXYY and 49, XXXXY syndrome. The features of these disorders are even more severe than Klinefelter syndrome. As more is learned about these variants, they are studied separately and are considered as separate conditions.