Molecular analysis of two Inborn errors of steroidogenesis in cases of abnormal sexual development / Wajeet Nabil Sayed ; Supervised Mahmoud A. Amer , Khadiga M. Gaffaar, Mona Lotfi Essawi

Thesis (Ph.D.) - Cairo University - Faculty of Science - Department of Zoology

Abnormal sexual development (ASD) resulting in the birth of a child needs Early and proper diagnosis. Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive inborn errors of adrenocortical steroidogenesis that results in 46,XX DSD. More than 95% of cases with CAH are due to 21- hydroxylase deficiency (21-OHD).The wide range of clinical presentations of 21-OHD deficiency depends on specific mutations in the gene CYP21A2. On the other hand, 17Ý-HSD type 3 deficiency is an autosomal recessive form of 46,XY DSD. More than 20 mutations in the17Ý-HSD type 3 have been found. Except for a high prevalence in an isolated Arabic population, 17Ý-HSD type 3 deficiency is thought to be a rare disease. The present study revealed that, IVS2- 13C/AIIG (also termed intron 2 mutation) that found to be presented in a frequency of 38.6% (17/44) is the most common mutation among the studied cases. Coming in the second position is V281L with frequency of 18.2% (8alleles/44). The third is Q318X with frequency of 13.6% (6alleles/44). Coming in the fourth place is P30L with a ratio of 9.1% (4alleles/44). I172N comes in the sixth position with ratio of 6.4% (3alleles/44)

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