Pseudoautosomal inheritance

Question 1

An unusual phenomenon known as ____ is observed with a sex chromosome - linked condition, _____, for w/c the underlying gene is located within the pseudoautosomal region of the short arm of the X chromosome.

Answer 1

pseudoautosomal inheritance; , Léri – Weill dyschondrosteosis

Question 2

As the 29 genes located within the PARs escape X inactivation (w/ the exception of the two most proximal PAR2 genes) and are present on both the X and Y chromosomes, mutations within these genes are inherited in an autosomal - like fashion, termed ____.

Answer 2

pseudoautosomal

Question 3

Only one PAR gene has been clearly associated w/ a clinical condition, the ____ gene, located within PAR1 on Xp and Yp.

Answer 3

SHOX

Question 4

Mutational inactivation or deletion of one copy of the _____ gene results in ____ syndrome, in w/c there is short stature & a characteristic ____ deformity at the wrist that includes bowing of the radius & dorsal dislocation of the distal ulna.

Answer 4

SHOX; Léri – Weill dyschondrosteosis; Madelung

Question 5

A more severe condition, known as ____, results in individuals who are homozygous for inactivating mutations of the SHOX gene.

Answer 5

Langer mesomelic dysplasia

Question 6

Haploinsufficiency of the same gene (SHOX) is believed to be responsible for the short stature and skeletal anomalies that occur in ____.

Answer 6

Turner syndrome

Question 7

It is possible that haploinsufficiency of other X chromosome genes in Turner syndrome partly alleviates the effects of the SHOX deficiency or that, in girls with SHOX deficiency alone (and therefore normal gonadal function), the ____ action at the growth plate may exacerbate the effects of SHOX haploinsufficiency.

Answer 7

oestrogen