Tag: turner syndrome

Sex determination


Sex determination


→ Sex of the baby is determined by SRY gene.

→ SRY gene is present on the distal end of short arm of Y- chromosome.

→ If it is present (Y chromosome) then it is male baby; if absent then female.

→ E.g. Turner syndrome- 45 XO- Y is missing, female baby.

→ E.g. Klinefelter’s syndrome- 47 XXY- Y is present, male baby.

→ Genes favor testes development is: SOX-9

→ Genes favor Ovaries development are: RSPO-1, WnT-4

Barr body test


Barr body test


→ No. of Barr Bodies = no. of X-chromosome − 1

Condition No. Of Barr Bodies
→ Normal male 1 – 1= 0
→ Normal female 2 – 1= 1
→ Turner Syndrome (45XO- Females) 1 – 1 = 0
→ Klinefelter’s Syndrome (47XXY- Males) 2 – 1 = 1
  • Therefore, it’s not a best method to determine the sex.
Malcare WordPress Security