Turner Syndrome

Question 1

Genetic defect of TS

Answer 1

45 X0 (50%), 50% partial X or isochromosome X

Question 2

common heart defects of TS

Answer 2

Coarc of aorta, ASD, bicuspid aortic valve

Question 3

Associated defects

Answer 3

webbed neck
short stature
shield-shaped chest, wide-spaced nipples
infertility

Question 4

antenatal US findings of TS

Answer 4

fetal edema of the neck, hands, or feet or
cystic hygroma

Question 5

Treatment of short stature for TS

Answer 5

GH therapy

Question 6

Incidence of TS

Answer 6

1 in 2500 live-born females

Question 7

Treatment for short stature/growth failure in TS?

Answer 7

• GH replacement therapy - recombinant GH injections
• steroid replacement - oxandrolone

Question 8

Treatment for delayed puberty in TS?

Answer 8

estrogen replacement for development of secondary sexual characteristics.

Question 9

% of girls with TS where 45 chromosomes with only one X chromosome?

Answer 9

about 50%

Question 10

Increase the risk of gonadoblastoma in TS?

Answer 10

presence of Y chromosome sequence

Question 11

Maternal age increase the incidence of TS, True or False?

Answer 11

False

Question 12

What is the chromosome defect of TS?

Answer 12

complete or partial loss of the paternal X chromosome.

Question 13

Renal anomalies of TS

Answer 13

• horseshoe kidney
• duplicated pelvis and ureters
• renal aplasia
• increase in number of renal vessels
• abnormal renal vessel course
• malposition

Question 14

Is pregnancy possible with TS?

Answer 14

Yes, if puberty is achieved, the uterus is normal and pregnancy is possible with the use of donated ova.

Question 15

Biochemical and clinical findings of streaked ovaries in TS?

Answer 15

• low estrogen
• high gonadotrophins (FSH, LH)
• failure of menstruation
• infertility

Question 16

Neonatal presentation of TS.

Answer 16

• Transient congenital lymphedema present over the dorsum of the feet.
• SGA - short at birth
• feeding difficulties

Question 17

Facial findings in TS

Answer 17

• anti-mongoloid slant (down slanting palpebral fissures)
• ptosis
• micrognathia
• dental malocclusion
• prominent ears, dysplastic ears
• conductive hearing loss (due to chronic middle ear infection)
• webbed neck
• low posterior hairline
• high-arched palate

Question 18

Neurological findings in TS

Answer 18

• MR is uncommon
• space-form perception defect

Question 19

Endocrine findings in TS

Answer 19

• increase incidence of autoimmune diseases (particularly hypothyroidism)
• infertility and pubertal failure due to streaked ovaries (ovarian dysgenesis)
• short stature

Question 20

Mean final height of TS

Answer 20

142-147 cm (+/- 12 cm)

Question 21

Dermatological/Skin findings in TS

Answer 21

• excessive pigmented naevi
• increased body hair especially in the extensor surfaces of lower arms

Question 22

What is the role of oxandrolone in TS?

Answer 22

Oxandrolone is an anabolic steroid with minimal androgenic side-effects which will increase final height when administered in low doses.

Question 23

How much increase in height when TS is treated with GH?

Answer 23

increase final height by 6-8 cm.

Question 24

Higher doses in required in TS than in GH deficiency to treat growth failure.

Answer 24

True

Question 25

Treatment for pubertal failure in TS?

Answer 25

estrogen replacement

Question 26

What is the role of estrogen replacement in TS?

Answer 26

* starts at 12-13 years for the development of secondary sexual characteristics * once puberty is initiated, cyclical therapy with estrogen and progesterone leads to menstrual cycles.

Question 27

TS pregnancy treatment

Answer 27

* ovum induction * and in vitro fertilization

Question 28

What syndrome is previously called male TS?

Answer 28

Noonan's syndrome

Question 29

Why DMD can occur in females with TS?

Answer 29

DMD is a sex-linked recessive disorder with the lesion on the dystrophin gene on the short arm of the X chromosome in the region of Xp21. It may occur in a milder form due to lyonisation.

Question 30

Does the use of estrogen increase adult height in TS? Why?

Answer 30

No. Estrogen accelerate the closure of the epiphyseal cartilage thus early end to growth.

Question 31

How many % of TS retain sufficient ovarian function for puberty to commence?

Answer 31

about 10%

Question 32

Skeletal findings in TS?

Answer 32

* short stature * shield-shaped chest, wide-spaced nipples * wide carrying angle (cubitus valgus) * short fourth metacarpal and hyperconvex nails * hypoplastic dermatoglyphics

Question 33

What is hypergonadotrophic hypogonadism?

Answer 33

Also known as Primary hypogonadism. It is a condition where the gonads don't produce enough sex steroids to suppress the secretion of FSH and LH.

Question 34

% of TS pregnancies that resulted in miscarriage?

Answer 34

about 90%

Question 35

How to monitor the growth of TS?

Answer 35

plot height and weight on a TS growth chart

Question 36

Examples of space-form perception defect in TS

Answer 36

* difficulty in directional sense - like driving a motor vehicle * nonverbal learning disorder - mathematics

Question 37

Describe TS with X0 or X-variantX

Answer 37

TS with karyotype of X0 or X-variantX will have otherwise normal female internal structures and also have normale female external genitalia. Mullerian duct development depends upon the absence of a functioning testes found on the SRY gene of Y chromosome.

Question 38

Describe 46XX/45X0 or 46XY/45X0 mosaicism.

Answer 38

Patients have streaked ovary (as in TS) and a testis (which may be dysgenetic or fully functional) and often have phenotypic features of TS.

Question 39

Routine investigations for short stature/slow growth

Answer 39

1. FBC with ferritin/iron and ESR/CRP 2. serum free thyroxine and TSH 3. serum creatinine 4. serum calcium, phosphate

Question 40

Genetic factors that causes short stature

Answer 40

* constitutional short stature * familial short stature * Turner's syndrome * Noonan's syndrome * Down's syndrome * Prader-Willi syndrome