Disorders of sexual development Flashcards
Topic: Normal Sexual Development
Question: Which gene on the Y chromosome is considered the testis-determining factor?
A. RSY
B. SRY
C. TDF
D. SDT
Correct Answer: B. SRY
Explanation: The SRY (sex-determining region Y) gene on the Y chromosome is considered the testis-determining factor.
Memory Tool: Think of SRY as “Sorry, you’re a Y (male).”
Question: At what weeks of gestation do the Sertoli cells of the testis secrete anti-Müllerian hormone (AMH)?
A. 1-2 weeks
B. 7-8 weeks
C. 9-10 weeks
D. 12-13 weeks
Correct Answer: B. 7-8 weeks
Explanation: The Sertoli cells of the testis secrete anti-Müllerian hormone (AMH) at 7 to 8 weeks of gestation.
Memory Tool: “AMH arrives at 7-8, just like breakfast.”
Topic: Embryologic Origins of Genital Structures (Table 10.1)
Question: What is the embryonic structure that gives rise to the ovarian ligament and round ligament of uterus?
A. Gonadal cortex
B. Rete ovarii
C. Gubernaculum
D. Paradidymis
Correct Answer: C. Gubernaculum
Explanation: The embryonic structure that gives rise to the ovarian ligament is the Gubernaculum.
Memory Tool: “Governors (Gubernaculum) always have ties (ligaments) to females (ovaries).”
Question: What is the embryologic origin of the female urethra?
A. Urogenital sinus
B. Müllerian duct
C. Wolffian duct
D. Gonadal medulla
Correct Answer: A. Urogenital sinus
Explanation: The embryologic origin of the female urethra is the urogenital sinus.
Memory Tool: “Uro-genital sinus takes U to the restroom.”
Topic: Disorders of Sexual Development (DSD)
Question: Which term is most widely used for conditions of abnormal sexual differentiation?
A. Intersex
B. Disorders of Sexual Differentiation
C. Difference of Sex Development
D. Disorders of Sexual Development
Correct Answer: D. Disorders of Sexual Development
Explanation: The most widely used terminology is Disorders of Sexual Development (DSD).
Memory Tool: “When it comes to terminology, DSD is the VIP.”
Topic: Diagnosis and Management in the Newborn with Ambiguous Genitalia
Question: What is the mean stretched penile length in a full-term newborn male in the United States?
A. 2.5 cm
B. 3.5 cm
C. 4.5 cm
D. 5.5 cm
Correct Answer: B. 3.5 cm
Explanation: The mean stretched penile length in a full-term newborn male in the United States is 3.5 cm (±0.04).
Memory Tool: “Newborn boys start at 3.5, just like the beginning of a race.”
Question: Which hormone levels should be checked immediately in a newborn with ambiguous genitalia? (Choose all that apply)
A. Serum electrolytes
B. 17-hydroxyprogesterone
C. Testosterone
D. Follicle-stimulating hormone (FSH)
Correct Answer: A, B, C, D
Explanation: Immediate serum laboratory evaluation includes karyotype, serum electrolytes, 17-hydroxyprogesterone, testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH).
Memory Tool: “For ambiguous newborns, remember the EFT Duo: Electrolytes, 17-hydroxyprogesterone, Testosterone, and the Duo of LH and FSH.”
Topic: Disorders of Gonadal Differentiation and Development
Question: What is the risk of germ cell tumors in 46,XY complete “pure” gonadal dysgenesis (Swyer syndrome) by 30 years of age?
A. 10%
B. 20%
C. 35%
D. 50%
Correct Answer: C. 35%
Explanation: The risk of germ cell tumors in 46,XY complete “pure” gonadal dysgenesis (Swyer syndrome) is up to 35% by 30 years of age.
Memory Tool: “Think of Swyer as a 30-year-old with a 35% off coupon for trouble.”
Question: What is the term used to describe the presence of both ovarian and testicular tissue in an individual?
A. Hermaphroditism
B. Ovotestis
C. Gonadal dysgenesis
D. Pseudohermaphroditism
Correct Answer: B. Ovotestis
Explanation: The term “Ovotestis” is used to describe the presence of both ovarian and testicular tissue in an individual.
Memory Tool: “Ovo” for ovary and “testis” for testicle; combined, they create “Ovotestis.”
Topic: Diagnosis and Management for the Older Child with Suspected DSD
Question: What is the first-line diagnostic modality for evaluating internal genitalia in a child with suspected DSD?
A. MRI
B. Ultrasound
C. CT scan
D. X-ray
Correct Answer: B. Ultrasound
Explanation: Ultrasound is the first-line diagnostic modality for evaluating internal genitalia in children with suspected DSD.
Memory Tool: “When in doubt, sound it out (Ultrasound).”
Question: Which medication is commonly used to suppress puberty in children with suspected DSD?
A. Leuprolide
B. Spironolactone
C. Clomiphene
D. Finasteride
Correct Answer: A. Leuprolide
Explanation: Leuprolide is commonly used to suppress puberty in children with suspected DSD.
Memory Tool: “Leuprolide puts puberty on ‘Lieu’-leave.”
Topic: Specific Pathophysiology and Management of Various DSD (Tables 10.3-10.4)
Question: What is the most common cause of 46,XX DSD?
A. Turner Syndrome
B. Androgen Insensitivity Syndrome
C. Congenital Adrenal Hyperplasia
D. Klinefelter Syndrome
Correct Answer: C. Congenital Adrenal Hyperplasia
Explanation: The most common cause of 46,XX DSD is Congenital Adrenal Hyperplasia (CAH).
Memory Tool: “CAH takes the XX crown.”
Question: Which mutation is commonly found in patients with Kallmann Syndrome?
A. FGF8
B. KAL1
C. GNRHR
D. NR5A1
Correct Answer: B. KAL1
Explanation: The KAL1 gene mutation is commonly found in patients with Kallmann Syndrome.
Memory Tool: “KAL1 is the key to Kallmann’s door.”
Question: What is the standard treatment for 5-alpha reductase deficiency?
A. Androgen therapy
B. Estrogen therapy
C. Surgical reconstruction
D. Gonadectomy
Correct Answer: A. Androgen therapy
Explanation: The standard treatment for 5-alpha reductase deficiency is androgen therapy.
Memory Tool: “Five Alpha needs an A (Androgen).”
Topic: Genital Ambiguity in the Newborn (Table 10.5)
Question: What is the most common cause of genital ambiguity in the newborn?
A. Androgen Insensitivity Syndrome
B. Congenital Adrenal Hyperplasia
C. Mixed Gonadal Dysgenesis
D. 5-alpha reductase deficiency
Correct Answer: B. Congenital Adrenal Hyperplasia
Explanation: Congenital Adrenal Hyperplasia is the most common cause of genital ambiguity in the newborn.
Memory Tool: “In newborn ambiguity, CAH is the usual suspect.”
Question: What initial tests are recommended for assessing genital ambiguity in the newborn?
A. Chromosome analysis and ultrasound
B. Chromosome analysis and hormone levels
C. MRI and ultrasound
D. Hormone levels and MRI
Correct Answer: B. Chromosome analysis and hormone levels
Explanation: Initial tests for assessing genital ambiguity in the newborn include chromosome analysis and hormone levels.
Memory Tool: “Newborn ambiguity? Check the ABCs: Analysis of Chromosomes and hormones.”
Question: What age is recommended for elective gonadectomy in children with DSD and Y chromosome material?
A. Before puberty
B. After puberty
C. At the time of diagnosis
D. Age is not a factor
Correct Answer: A. Before puberty
Explanation: It is recommended to perform elective gonadectomy in children with DSD and Y chromosome material before puberty.
Memory Tool: “Before the teen years tick, remove the Y-linked risk.”
Question 3: Hormonal Influence in Development
Topic: Hormones in Sexual Development
Vignette: A pediatric urologist encounters a newborn boy with abnormal genitalia. The doctor suspects a problem with the boy’s hormonal development during gestation.
Multiple-Choice Options:
A. Anti-Müllerian hormone is secreted at 12–13 weeks of gestation.
B. Androgens promote virilization of wolffian duct structures at approximately 6 weeks of gestation.
C. Testosterone secretion by the fetal testis Leydig cells occurs at approximately 9 weeks of gestation.
D. Sertoli cells secrete testosterone at 7–8 weeks of gestation.
Correct Answer: C. Testosterone secretion by the fetal testis Leydig cells occurs at approximately 9 weeks of gestation.
Explanation: Testosterone secretion by the fetal testis Leydig cells occurs at about 9 weeks of gestation, promoting virilization of wolffian duct structures.
Memory Tool: “9 weeks for 9 Lives of Testosterone” to remember when Leydig cells start secreting testosterone.
Reference Citation: Paragraph 6
Rationale: This question evaluates the examinee’s understanding of the timing and hormonal influences affecting sexual development, essential for diagnosing and managing DSD.
Question 2: Common Embryologic Origins of Genital Structures
Clinical Vignette: A pediatric urologist is consulting on a newborn with ambiguous genitalia and is asked about the embryological origin of the testis.
A. Indifferent Gonad
B. Gonadal cortex
C. Gonadal medullar
D. Mesonephric tubules
Correct Answer: A
Explanation: The testis originates from the Indifferent Gonad according to Table 10.1.
Memory Tool: “Indifferent Gonad isn’t indifferent about becoming a Testis.”
Reference: Table 10.1
Rationale: Knowledge of embryological origins is essential for understanding the possible etiologies and management strategies for ambiguous genitalia and other DSDs.
Question 3: Hormones in Sexual Development
Clinical Vignette: An endocrinologist is treating a young patient with a suspected DSD and wants to confirm the role of certain hormones in male sexual development.
A. Anti-Müllerian hormone is secreted by Leydig cells
B. Testosterone secretion by Leydig cells occurs at approximately 6 weeks of gestation
C. DHT binds to the receptor with less affinity and stability than testosterone
D. Sertoli cells secrete anti-Müllerian hormone at 7 to 8 weeks of gestation
Correct Answer: D
Explanation: The Sertoli cells of the testis secrete anti-Müllerian hormone (AMH) at 7 to 8 weeks of gestation.
Memory Tool: “Sertoli secretes to Stop Müllerian” (Sertoli secretes anti-Müllerian hormone)
Reference: Paragraph 5
Rationale: Understanding the hormonal regulation in sexual development is crucial for the diagnosis and management of DSDs.
Question 4: Urethral Development
Clinical Vignette: A urologist is consulted for a newborn with a suspected urethral anomaly. The physician wants to confirm the embryological origin of the spongy urethra.
A. Derived from the endoderm
B. Derived from the mesoderm
C. Derived from the ectoderm
D. Derived from both endoderm and mesoderm
Correct Answer: A
Explanation: The spongy urethra is derived from the endoderm, as per Table 10.1.
Memory Tool: “Endoderm is the End-all for Spongy Urethra.”
Reference: Table 10.1
Rationale: Understanding the embryological origin of urethral structures aids in the diagnosis and management of congenital urethral anomalies.
Question 5: Disorders of Sexual Development
Clinical Vignette: A pediatrician is evaluating a newborn girl with clitoromegaly. The physician is considering the most common cause of 46,XX DSD.
A. Androgen Insensitivity Syndrome
B. Congenital Adrenal Hyperplasia
C. Mixed Gonadal Dysgenesis
D. 5-alpha reductase deficiency
Correct Answer: B
Explanation: Congenital Adrenal Hyperplasia is the most common cause of 46,XX DSD, as indicated in paragraph 8.
Memory Tool: “Bigger CAHuse, Bigger Clitoris” (CAH most common in 46,XX with clitoromegaly)
Reference: Paragraph 8
Rationale: Identifying the most common causes of DSD helps in formulating a differential diagnosis and guiding further evaluation and management.
Question 6: Types of Hypospadias
Clinical Vignette: A urologist is evaluating a 1-year-old boy for hypospadias and wants to recall the classification based on the location of the meatus.
A. Penoscrotal hypospadias is the most common type
B. Glandular hypospadias is the most severe form
C. Subcoronal hypospadias is the least severe form
D. Glandular hypospadias is the most common type
Correct Answer: D
Explanation: Glandular hypospadias is the most common type, according to Table 10.2.
Memory Tool: “Glandular is Grand-ular” (most common type)
Reference: Table 10.2
Rationale: Understanding the classification of hypospadias is essential for surgical planning and counseling families.
Question 6: Disorders of Gonadal Differentiation and Development - Klinefelter syndrome
Clinical Vignette: A 20-year-old male presents with small testicles and gynecomastia. He is found to have azoospermia upon further testing.
A. What is the most likely diagnosis?
A) Turner syndrome
B) Klinefelter syndrome
C) Gonadal dysgenesis
D) 46,XX male
E) 46,XY complete “pure” gonadal dysgenesis (Swyer syndrome)
Correct Answer: B) Klinefelter syndrome
Explanation: The classical presentation of Klinefelter syndrome includes small and firm testicles, gynecomastia, and azoospermia.
Memory Tool: Think of “Klein” as “small” for small testicles, and “felter” as “felt her” for gynecomastia.
Reference Citation: Paragraph on Klinefelter syndrome
Rationale: This question assesses your knowledge about one of the most common major abnormalities of sexual development, which is relevant for diagnosis and management.