V. C. Shah

Cytogenetic studies in a population suspected to have chromosomal abnormalities

The present study describes the cytogenetic findings in cases suspected with chromosomal abnormalities, in cases of mental retardation, multiple congenital malformations, clinical features of Down’s syndrome, Klinefelters’s syndrome, Turner’s syndrome, ambiguous sex, sterility, amenorrhea and history of repeated spontaneous abortions in couples. Cytogenetic studies were done in 144 of the total 205 cases. In all, 57 (39.58%) were shown to have chromosomal abnormality and of these, 34 cases (25.7%) were Down’s syndrome. Sex chromosome abnormality was found in 19 cases (13.2%). The results confirm the significant contribution of chromosomal abnormalities in the genesis of mental retardation, and abnormal sexual development.

Three siblings with Harlequin Ichthyosis in an Indian family

The Harlequin fetus is a distinct genetic entity with a strikingly grotesque appearance. Three siblings (two males, one female) with Harlequin Ichthyosis, a rare form of congenital disorder, born to the same parents are presented. The genetic aspects are discussed and the relevant literature is reviewed.

Incomplete Gonadal Dysgenesis

A 21-year-old phenotypic male with ambiguous external genitalia and hypospadias was referred for cytogenetic studies. Exploratory laparotomy revealed presence of a small atropic uterus, unilateral gonadal dysgenesis with fallopian tubes on both sides and a cryptorchid testis on the left side. No gonad could be traced on the right side. Chromosomal analysis from peripheral whole blood culture revealed a 46,XY cell line. No mosaicism was detected. Endocrine studies showed elevated levels of serum FSH and LH with low borderline testosterone level and failure to respond to HCG stimulation. The presence of fallopian tube next to testis suggests absence of anti-Mullerian hormone secretion by Sertoli cells. The absence of Wolffian duct derivatives indicates insufficient secretion of testosterone by Leydig cells.

Down syndrome in Ahmedabad: Karyotype analysis in 60 cases

A total of 100 cases suspected to have Down syndrome (DS) were clinically evaluated. Giemsa trypsin karyotype analysis were carried in 72 patients and chromosome abnormality was confirmed in 60 patients. Fifty four had standard trisomy 21, two had translocations: one with t (21q 21q) (de novo) and other with t (14q 21q) mat. Mosaicism was found in four patients. In 45 cases the maternal age was <-30 years and in 15 the maternal age was >30 years., Variants (polymorphism) for D and G group chromosomes were found in eight patients and their parental origin were confirmed. Congenital heart disease, duodenal atresia, cataract, polydactyly and amino aciduria were found to be associated with some of the patients. A very rare and unusual case of “absent patellae” was found in a female DS with trisomy 21. The frequencies of different types of chromosomal abnormalities in Down syndrome in our study is comparable to the reports in other parts of the country. A precise cytogenetic diagnosis in DS enables the prognosis, better management and genetic counselling to the affected families.

Trisomy 21 q: 46,XX,21s+/47,XX,+21q−(q22→qter) mosaicism (de novo) in a down syndrome child

A three year old girl with clinical features of Down syndrome and mental retardation is reported. Karyotype of the proband was 46,XX,21s+/47,XX,21q→(q22−qter), resulting in partial trisomy for chromosome 21. Her father, phenotypically normal, was a carrier for 21s+variant chromosome (46,XX,21s+). The maternal age was 32 years. This case further confirms that the Down phenotype is due to the trisomy of the distal segment of the band q22 of chromosome 21.

True hermaphrodite: 46, ;XX/46, XY, clinical, cytogenetic and histopathological studies

A case of unilateral ovo-testicular intersex in a five year old phenotypically male child referred for ambiguous genitalia is reported. General abnormalities included a prominent phallus, fusion of labia, bifid scrotum, absence of urethral opening and corpus. Gonads were not palpable. X and Y chromatin was found to be positive. Chromosome studies revealed 46, XX!46, XY karyotype. Laparotomy findings confirmed true hermaphroditism. The findings are compared and discussed with cases reported in the literature

Unilateral gonadal dysgenesis with both testis and fallopian tube on the same side in a 45,X/46,X INV (Y) mosaic male

SummaryA 5-year-old male with ambiguous external genitalia, hypospadias and microphallus without an urethral orifice was referred for cytogenetic studies. Exploratory laparotomy revealed presence of an infantile uterus and unilateral gonadal dysgenesis with both testes and fallopian tube on the right side. The metaphase cells from peripheral blood culture showed both 45,X/46,X inverted Y (p11.2q11.23) cell-lines (98:2). The inverted Y was found to be of paternal origin. Maternal chromosomal pattern was normal 46,XX. The presence of a fallopian tube next to testis suggest absence of secretion of anti-Mullerian hormone by Sertoli cells. The absence of Wolffian duct derivatives suggest insufficient secretion of testosterone by Leydig cells.

Hypospadias and gynecomastia in a male associated with autosomal balanced translocation

A 17-yr-old boy presented with hypospadias and gynecomastia. His secondary sexual characters were poorly developed: small phallus, bilateral atrophic testes, absence of beard and moustache, axillary hair, feminine distribution of public hair and marked enlargement of breats. Laparotomy findings showed absence of ovaries, fallopian tubes and uterus. Histopathology of the testes showed spermatogenic arrest, distorted tubules and epidymis, and very few leydig cells. Cytogenetic studies showed, 45, XY, −13, −14, +t (13q; 14q)karyotype in cultured lymphocytes and gonadal fibroblast culture. His LH, FSH and prolactin hormone levels were within normal range. The case report suggests the possible interaction of autosomal genes in the human sexual development.