Table of Contents

INTRODUCTION

NORMAL SEX DETERMINATION AND DIFFERENTIATION

Genetic Sex

Establishment of Common, Undifferentiated Structures

Gonadal Sex

Fetal Production of Gonadal Hormones

External Genitalia

DISORDERS OF SEX DEVELOPMENT (DSD)

46,XY DSD

46,XY DSD due to Gonadal Dysgenesis

46,XY DSD due to Deficiency of Testosterone Biosynthesis

46,XY DSD due to 5α-Reductase-2 Deficiency

46,XY DSD due to Abnormal Androgen Receptor Activity

46,XX DSD

Abnormal Fetal Androgen Production: Congenital Adrenal Hyperplasia (CAH)

Excess Maternal Androgen Production

Placental Aromatase Deficiency

Drugs administered to the mother during gestation

Other Categories of DSDs

DSDs Associated with Multiple Congenital Anomalies

Ovotesticular DSD

DSDs and Sex Chromosome Aneuploidy

WORK-UP OF INFANTS BORN WITH AMBIGUOUS GENITALIA

Clinical Review and Evaluation

Status of body hydration

Obtain a karyotype

Hormone studies

Imaging Studies

Molecular Studies

DIFFERENTIAL DIAGNOSIS

46,XX DSD

46,XY DSD

SEX OF REARING

Sex Assignment for Newborns Affected by 46,XX DSDs

Sex Assignment for Newborns Affected by 46,XY DSDs

SUMMARY