Limb disorders

Gene: THPO

I don't know

Comment on list classification: Promoting from red to amber. Two cases of Thrombocythemia with limb defects and variants in THPO reported.

Created: 20 Nov 2019, 12:20 p.m. | Last Modified: 20 Nov 2019, 12:20 p.m.

Panel Version: 1.63

Associated with Thrombocythemia 1 #187950 (AD) in OMIM.


PMID: 19553636 - Graziano et al 2009 - report where the father has thrombocythemia and limb defects (absence of forearm and hand, absence of foot). Two sons had milder lower limb defects. A G185T heterozygous mutation was detected in THPO. The grandfather was found to have the variant and had thrombocythemia but no limb defect.

PMID: 22453305 - Stockklausner et al 2012 - report two families with Hereditary thrombocythemia resulting from a THPO c.13+1 G>C mutation in the splice donor of intron 3. In one family there were coexisting distal limb defects in 2 out of 4 individuals with thrombocythemia (complex limb defects of the left hand in one individual, and absent proximal, middle, and distal phalanges at digits 3–5, a dysplastic proximal phalanx at digit 2 with absent middle and distal phalanx and shortened metacarpal bones at digits 3 and 4, carpal bones were partly fused to metacarpal bones at digits 2–5 in the other).

Two cases reported with a limb defect and no clear wider skeletal phenotype.
Sources: Literature

Created: 20 Nov 2019, 12:19 p.m.

Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown

Phenotypes
Thrombocythemia 1, 187950

Publications

• 19553636
• 22453305