Background: 5-α-ReDuctase (5ARD) deficiency, is an 
autosomal recessive diseases, resulting in the inability to 
produce the physiologically active DiHydroTestosterone 
(DHT) which is required for normal virilization of the 
male external genitalia. 
Material and Methods: This is a retrospective, hospital 
based study conducted over a 25 year period (1989-2014) 
at King Khalid University Hospital (KKUH), Riyadh, 
Saudi Arabia, where patient’s files with 46 XY, DSD 
diagnosed with 5-α-reductase deficiency were reviewed 
for the clinical characteristics and management. All 
patients
 were managed by an experienced 
multidisciplinary team. 
Results: During the period under review, a total of nine 
(16%) patients among the 56 patients, with 46 XY DSD 
were diagnosed hormonally, i.e. Human Chorionic Gonadotrophin (HCG) stimulated DHT / testosterone ratio 
of more than 35, to have 5-α-reductase deficiency. All 
patients presented with variable degrees of ambiguous 
genitalia. Unfortunately, three (33.3%) patients needed 
sex-reassignment. Their clinical characteristics and 
management were presented. 
Conclusion: In our community, with an increased 
prevalence of consanguineous matings and with multiple 
siblings, it is not that an uncommon to have such numbers 
of 5-α-reductase deficiency among those presenting with 
46 XY DSD, and should be considered as an important 
differential diagnosis. A multi-disciplinary team approach 
is essential for a successful management and better 
prognosis.