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45. What are the DSDs associated with eunuchoidal body proportions?

The DSDs associated with eunuchoidal body proportions include 46,XY

and 46,XX complete gonadal dysgenesis, androgen biosynthetic defects

(17β- HSD3, 17α-hydroxylase deficiency), and placental aromatase

deficiency.

46. How to classify gonadal dysgenesis?

Gonadal dysgenesis refers to defective development of gonads, which can vary

from hypoplastic and dysfunctioning gonads mainly composed of fi brous tissue

without any germ cells (ovarian-like stroma, i.e., streak gonads) to incomplete

gonadal development (dysgenetic gonads). Dysgenetic gonads commonly con-

tain hypoplastic seminiferous tubules and fi brous tissue (dysgenetic testis). The

differences between various types of gonadal dysgenesis are summarized in the

table given below.

Types Gonad Genitalia

Complete or pure gonadal

dysgenesis (46,XX or 46,XY)

Bilateral streak gonads External: female

Internal: female

Partial gonadal dysgenesis (46,XX

or 46,XY)

Bilateral dysgenetic gonads External: female to

ambiguous

Internal: commonly

female

Mixed gonadal dysgenesis

(45,X/46,XY)

Dysgenetic testis on one side

and streak on the other side

External: ambiguous

Internal: female/male

47. What are the somatic features associated with 46 , XY gonadal dysgenesis?

The presence of extragonadal manifestations provide clues to the diagnosis of

46,XY gonadal dysgenesis. These are summarized in the table given below.

Extragonadal manifestations Syndrome Mutation

Wilm’s tumor, aniridia, genitourinary

abnormalities

WAGR syndrome WT1

Wilm’s tumor and early-onset nephropathy Denys–Drash syndrome WT1

Late-onset nephropathy Frasier syndrome WT1

Skeletal anomalies Camptomelic dysplasia SOX9

Mental retardation – WNT4, DMRT1,

ATRX

α-Thalassemia – ATRX

9 Disorders of Sex Development