DSD & Steroid Hormone Synthesis Flashcards
The term “genetic sex” in a newborn infant refers to whether it has…
a copy of the SRY gene
At the target tissue, virilization is mediated by
A. Androstenedione
B. Dehydroepiandrosterone
C. Dihydrotestosterone
D. Testosterone
C. Dihydrotestosterone
Anti-Mullerian hormone is secreted by the
A. Bipotential gonadal ridge cells
B. Grandulosa cells
C. Leydig cells
D. Sertoli cells
E. Theca Cells
D. Sertoli cells
The differentiation of Sertoli and Leydig cells establish the developing gonad as a testis and their products drive the rest of male development. The Sertoli cells begin by secreting AMH (anti-Mullerian hormone), which causes the paramesonephric duct to regress, while the Wolffian duct persists. Meanwhile, the Leydig cells in turn produces testosterone and insulin-like peptide 3, which promote differentiation of the Wolffian ducts into the epididymis, vas deferens and seminal vesicles. In addition i mediates the descent of the testes through the internal inguinal ring
Which is least likely to be associated with infertility?
A. A person with 46,XY and 21-hydroxylase deficiency
B. A person with 46,XX and 21-hydroxylase deficiency
C. Complete androgen insensitivity
D. Klinefelter syndrome
E. Turner syndrome
A. A person with 46,XY and 21-hydroxylase deficiency
congenital adrenal hyperplasia (CAH)
virilization for XX b/c of excess androgens
salt-wasting –> hypotension
21-hydroxylase deficiency:
deficiency of adrenal hormone synthesis
impairs aldosterone and cortisol synthesis
In the simple virilizing form, an affected female fetus demonstrates varying degrees of virilization at birth, such as clitoral enlargement, labial fusion, and development of a urogenital sinus leading to “ambiguous” genitalia at birth and occasionally gender assignment errors. Males show no genital abnormality at birth but may show precocious puberty (before 8-9 years old) in childhood with increased phallic growth and pubic hair development.
Most common genetic adrenal disorder
Which of the following is associated with mixed gonadal dysgenesis?
A. 45,X/46,XY
B. 45,X/47,XXX
C. 45,X/47,XXY
D. 46,XX/46,XY
E. 46,XY/47,XXY
D. 46,XX/46,XY
becuase these patients are chimerias due to two zygotes fusing
Which one of hte following disorders is associated with virilization during puberty?
A. 5alpha-Reductase deficiency
B. 21-Hydroxylase deficiency
C. Complete androgen insensitivity
D. Dax deficiency
E. Duplication of SRY gene
A. 5alpha-Reductase deficiency
boys with female external genitalia
presents at puberty with amennhoria and virilization
elevated testosterone: DHT ratio b/c 5-alpha reductase converts testosterone to DHT
46XY with testes and internal male genitalia b/c of testosterone but atypical or external female structures (lower 2/3 vagina, labia, clitoris) b/c no 5-alpha reductase converts testosterone to DHT
Which one of the following disorders are assocaited with hypertension?
A. 11-Hydroxylase deficiency
B. 21-Hydroxylase deficiency
C. DAX deficiency
D. Pseudohypoaldosternism
A. 11beta-Hydroxylase deficiency
hypertension& hypokkalemia in infancy
46XX: ambiguous genitalia at birth, virilization during puberty with precocious puberty (b/c of excess androgens)
2nd most common congenital adrenal hyperplasia
elevated deoxycorticosterone
What is the inheritance pattern of complete androgen insensitivity?
X-linked recessive
What is the inheritance pattern of androgen insensitivity syndrome?
X-linked recessive
typically affects genetic males
What is the role of 5-alpha reductase?
converts testosterone to dihydrotestosterone (DHT) (more potent than testosterone)
DHT is responsible for devlopment of male external development
Androgen Insensitivity Syndrome
Androgen Insensitivy Syndrome at Puberty
Most of the DSDs are AD, which one is different and what is its inheritance pattern?
Complete androgen insensitivity is X-linked recessive
