21-Hydroxylase Deficiency: Newborn Screening in Iran?

21-hydroxylase deficiency (21-OHD) accounts for the cause of 90-95% of congenital adrenal hyperplasia (CAH) cases. The world incidence of 21-OHD is 1:20,000 to 1:10,000 live births[1]. Prevalence of CAH trends to be high due to frequent consanguineous and first cousin marriages and underestimation because of stigmatization[2, 3]. A range of clinical phenotypes including salt-wasting, simple virilizing and non-classic forms is emerged due to the variable residual 21-hydroxylase enzyme activity in CAH. Enzymatic defects in steroid biosynthesis pathway leads to accumulation of the metabolic precursors and shifting to androgen synthesis. Ambiguous genitalia appear in infant girls[4]. Basically, salt-wasting form occurs between first and third week after birth[4]. Because of nonspecific symptoms, an accurate diagnosis is often delayed so that males with classic form are at serious risk of morbidity (including neurological damage or intellectual disability) and mortality[4, 5].