Klinefelter Syndrome Flashcards Preview

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Flashcards in Klinefelter Syndrome Deck (18)
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1
Q

Which type of endocrine abnormality is Klinefelter syndrome

A

Hypergonadotropic hypogonadism

2
Q

Incidence

A

1 in 600 live-born boys

3
Q

Karyotype of Klinefelter syndrome

A

47, XXY

4
Q

Sex/gender of Klinefelter syndrome

A

Male

5
Q

Stature/Size of a patient with klinefelter syndrome

A

taller than average

6
Q

Intelligence in Klinefelter

A

Marginally reduced compared with siblings

Falls within normal or low-to-normal limits

7
Q

Development in Klinefelter

A

Mild developmental delay (specially speech)

Behavioural problems

8
Q

Common features in Klinefelter syndrome

A

3 are low:

Lack of secondary sexual characteristics (or variable)

Small firm testes (hypogonadism)

Infertile (due to azoospermia & low testosterone)

3 are high:

Taller than average

Gynaecomastia (in 30% cases)

Elevated gonadotrophin levels

9
Q

Pre-pubertal and pubertal features in Klinefelter’s

A

Prepubertal: Rare phenotypes

At puberty:

variable secondary sexual sex characteristics

Poor growth of facial and body hair

Small testes

Azoospermia

10
Q

Atypical female-like features in Klinefelter

A

Female distribution of body fat and hair

Gynaecomstia (in 30%)

high pitched voice

(these are possible but not typical)

11
Q

Which cancer is more common in Klinefelter syndrome?

A

Breast cancer in male

(increases risk but not much high)

(Due to gynaecomastia)

12
Q

Lab findings in Klinefelter syndrome

A

LH >>>>> High

FSH >>>>> High

Testosterone >>>>> Low/normal

(At puberty, most cases has around testosterone 50% of normal level)

13
Q

Diagnostic test (Investigation of choice) for Klinefelter

A

Karyotyping

14
Q

Chromosomal abnormalities with tall stature

A

Klinefelter syndrome

Kallman syndrome

Marfan syndrome

15
Q

Chromosomal abnormalities with short stature

A

Turner syndrome

Noonan syndrome

Fragile X syndrome

16
Q

Differentiate Klinefelter’s & Kallman syndrome by hormonal findings

A

Klinefelter syndrome → high LH, high FSH, low testosterone (= hypergonadotropic hypogonadism)

Kallman syndrome → low LH, low FSH, low testosterone (= hypogonadotropic hypogonadism)

Mnemonic: Incline = Kline-felters → LH, FSH incline

Fall = ‘Kall’-man → All falls

17
Q

Testes in Kallman, Klinefelters and Fragile X

A

Kallman syndrome: cryptorchidism (undescended testes) or only few mm/ml

Klinefelter syndrome: small firm testes

Fragile X syndrome: Large testes

18
Q

How to differentiate between Kallman syndrome & Klinefelter syndrome by lab investigations?

A

Klinefelter syndrome: LH, FSH >>> high; Testorterone >>> low/low-normal

Kallman syndrome: LH, FSH >>> low-normal; Testosterone >>> low