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of androgens in a female XX masculinised
female Klinefelters are phenotypic males at birth. However due to the effect of the extra X chromosome during differentiation there is a failure of the secondary sexual characteristics leading to a eunachoid habitus and development of gynaecomastia. The sex chromosome complement in the Klinefelter syndrome was first described in 1959 2. Although Turners are phenotypic females the absence of a second X chromosome leads to failure in the development of the ovary resulting in streak gonads. Short stature and primary amenorrhoea are cardinal signs. The sex chromosome complement of the Turner syndrome was first described in 1959 3. The testicular feminisation syndrome is an X linked recessive disorder. These individuals have a XY sex chromosome constitution. Although a testis develops during foetal life the target organs are insensitive to the circulating foetal androgens leading to failure of the masculinisation of the external genitalia. They are brought up as females. At puberty breasts develop and they become attractive females of above average height. The testicular feminisation syndrome was first described in 1953 4. The syndrome of congenital adrenal hyperplasia an autosomal recessive disorder was first described in 1956 5. In this syndrome females are born with virilised external genitalia. The enzyme defects were described in 1962 6. Establishing the X chromosome number at birth can be life saving in the severe salt losing form of the disease. This study is an analysis of the X chromatin status in referrals suspected of having the Klinefelter, Turner, testicular feminisation and congenital adrenal hyperplasia syndromes. |
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Population and
method
Buccal smears of 25 phenotypic males and 201 phenotypic females were analysed. A modification of the method of Barr was used to prepare the buccal smears 7. The buccal smears were made by firmly scraping the mucosa of the cheek with a metal spatula. The scraping was smeared gently on a clean albuminised slide and fixed immediately in freshly prepared fixative consisting of equal volumes of ether and ethyl alcohol. Permanent preparations were made after staining with carbol fuchsin. Each slide was identified by a code number only. All smears were certified X chromatin positive or X chromatin negative by the author without reference to the designated sex of the referrals. Hundred large nuclei with smooth unbroken nuclear membranes were scored for the number of X chromatin bodies. A count of 10- 30 per 100 nuclei observed was taken as X chromatin positive and a count of two or less per 100 nuclei as X chromatin negative. More than one X chromatin body was not observed in any of the smears.
Table 1 gives the X chromatin status as negative or positive of the phenotypic males referred for suspected Klinefelter syndrome. The reason for referral was clinically suspected Klinefelter or gynaecomastia. Table 2 gives the X chromatin status as positive or negative of the phenotypic females referred for suspected Turner, testicular feminisation, and congenital adrenal hyperplasia syndromes. The reason for referral was clinically suspected Turner, testicular feminisation, congenital adrenal hyperplasia short stature or primary amenorrhea. |