Congenital adrenal hyperplasia (CAH) is a genetic disorder resulting from total or partial deficiency of an enzyme involved in cortisol and aldsosterone biosynthesis. In 95% of the cases of CAH, this enzyme is the 21-hydroxylase, which is responsible for the conversion of 17-hydroxyprogesterone to 11-deoxycorticsol. The deficiency of this enzyme leads not only to loss of cortisol synthesis, but also to the accumulation of cortisol precursors, and increase in ACTH, and consequently, androgen levels.
Al-Maghribi (2007) conducted a retrospective study on patients with congenital adrenal hyperplasia (CAH) over a period of 10 years (1996-2006) at the King Hussein Medical Center (KHMC) in Amman. The study included 73 Jordanian children (39 females and 34 males) with CAH.
Lubani et al. (1990) found 60 children with CAH diagnosed between 1978 and 1988, giving an estimated prevalence of 1 in 9,000 live births. In addition, there was presumptive evidence of CAH resulting in the death of 20 other children, giving a prevalence figure of 1 in 7,000. In 54 patients (90%), 21-hydroxylase deficiency was diagnosed.
Rajab et al. (2005) undertook a study to estimate the prevalence of commonly diagnosed autosomal recessive diseases in Oman from a hospital-based register in years 1993 to 2002. The study revealed that congenital adrenal hyperplasia was diagnosed in 55 patients, with an observed incidence of 1 in 10,000 births.
Sawardekar (2005) conducted a study to establish the prevalence of major congenital malformations in children born during a 10-year period in Nizwa Hospital. Of the 21,988 total births in the hospital, four children were born with congenital adrenal hyperplasia (21 OH deficiency).
Lindner et al. (2007) investigated 25,214 neonates born in Qatar for inborn errors of metabolism and endocrine disorders. One neonate was diagnosed with congenital adrenal hyperplasia.
Al-Jurayyan (2011) conducted a retrospective study in the pediatric endocrine clinic at a university hospital Saudi Arabia during the period 1989-2008. Medical records of 81 children with ambiguous genitalia were reviewed. Fifty three (65%) of the patients were genetically females (46XX), with congenital adrenal hyperplasia being the common cause in 51 (97%) patients.
In a study on 102 women of Arab and Asian origins with hirsutism, Gatee et al. (1996) identified late onset congenital adrenal hyperplasia due to 21-hydroxylase deficiency in two cases.