2 year old child presented with diarrhoea and failure to thrive, Blood examination shows - Na = 122, K-6. He is most probably suffering from

Patients with 21-hydroxylase deficiency are the most severly affected and present in neonatal period with virilization and salt wasting.Abnormal genital appearance should promot the diagnosis in girls.Diagnosis is often missed in boys as they lack specific clinical features.They present after second week of life with failure to thrive, polyuria, hyperpigmentation,and shock.Early diagnosis is mandatory to prevent moality.21-hydroxylase deficiency should be suspected in neonates with ambiguous genitalia,polyuria,shock,recurent vomiting and features of sepsis with negative septic screen. Reference: OP Ghai,essential paediatrics ,8 th edition,page no 526