A human female with Turner syndrome also expresses the Xlink

A human female with Turner syndrome also expresses the X-linked recessive hemophilia trait, as did her father. Which of her parents underwent non-disjunction during meiosis to give rise to the gamete responsible for the syndrome. Diagram your answer. A couple planning their family are aware that there has been a high incidence of stillbirths and children born with developmental abnormalities on the husband\'s side of the family. A karyotype analysis of the father shows a normal complement of 46 chromosomes, but one of the chromosomes contains an inversion covering 70% of its length. What is the probability that the couple will have a child with no developmental abnormalities?

Solution

A human female with Turner syndrome expresses the X-linked trait hemophilia as did her father. Which of her parents underwent non disjunction during meiosis, giving rise to the gamete responsible for the syndrome?

Answer =. her mother

Turner syndrome-genotype-------45,XO

For expression haemophilia, one X-linked recessive allele is enough for expression in males.

For expression haemophilia, TWO X-linked recessive allele is required for expression in females.

Turner syndrome genotype = X^hO

X^h

O

X^{h    RECEIVED FROM FATHER}

O ^{RECEIVED FROM MOTHER DUE TO} disjunction

X^hO

Xh		O
Xh    RECEIVED FROM FATHER		O RECEIVED FROM MOTHER DUE TO disjunction
	XhO