5 -Reductase 2 deficiency

== 5_-Reductase 2 Deficiency ==

5_-Reductase 2 deficiency is a rare genetic disorder that affects the development of male sexual characteristics. It is caused by mutations in the SRD5A2 gene, which encodes the enzyme 5_-reductase type 2. This enzyme is responsible for converting testosterone into dihydrotestosterone (DHT), a more potent androgen that plays a crucial role in male sexual differentiation.

Genetics

The condition is inherited in an autosomal recessive pattern, meaning that an individual must inherit two copies of the mutated gene, one from each parent, to be affected. Carriers, who have only one copy of the mutation, typically do not show symptoms.

Pathophysiology

In individuals with 5_-reductase 2 deficiency, the lack of DHT during fetal development leads to incomplete masculinization of the external genitalia. Affected individuals are genetically male (46,XY) but may be born with ambiguous genitalia or female-appearing genitalia.

Clinical Features

At birth, individuals with 5_-reductase 2 deficiency may present with ambiguous genitalia, such as micropenis, hypospadias, or a bifid scrotum. During puberty, some affected individuals may experience virilization, including increased muscle mass, deepening of the voice, and growth of facial and body hair, due to increased testosterone levels.

Diagnosis

Diagnosis of 5_-reductase 2 deficiency is based on clinical examination, hormonal assays, and genetic testing. Elevated testosterone to DHT ratio in the blood is a key diagnostic marker. Genetic testing can confirm mutations in the SRD5A2 gene.

Management

Management of 5_-reductase 2 deficiency involves a multidisciplinary approach, including endocrinologists, urologists, and psychologists. Treatment options may include hormone replacement therapy, surgical correction of genital anomalies, and psychological support.

Prognosis

The prognosis for individuals with 5_-reductase 2 deficiency varies depending on the degree of genital ambiguity and the individual's response to treatment. With appropriate management, individuals can lead healthy lives.

Related Pages

• Androgen insensitivity syndrome
• Congenital adrenal hyperplasia
• Intersex
• SRD5A2 gene