Limb disorders

Gene: TBX22

Comment on list classification: Kept rating as Red: there is some evidence linking limb anomalies to TBX22 variants (PMID:21375406) but currently insufficient cases for inclusion on a diagnostic panel.

Created: 11 Oct 2018, 10:41 a.m.

Abruzzo-Erickson syndrome (MIM:302905, reported by Abruzzo and Erickson in 1977, PMID:839509) includes radial synostosis (an abnormal connection (synostosis) of the radius and ulna (bones in the forearm) at birth). In affected family members (2 brothers and an uncle) with Abruzzo-Erickson syndrome, Pauws et al. 2013 (PMID:22784330) identified a -5T-A transversion in intron 3 (c.593-5T-A) of the TBX22 gene- a dactyly phenotype isn't mentioned by Pauws et al.

Created: 11 Oct 2018, 9:45 a.m.

PMID:21375406 (Kaewkhampa, 2012) identified a hemizygous missense c.452G>T (p.Arg151Leu) variant in a 9 year old Thai boy who had unilateral complete cleft lip and palate and additional features including hypoplastic right thumb and clinodactyly of the fifth digits and the right index finger. In addition, he displayed carpal bone anomalies consisting of hypoplastic trapezoid, trapezium of the left hand, and shortness of the first proximal phalange and the first metacarpal. The trapezium and scaphoid of the right hand were absent. The authors say this is the first case of limb anomalies reported with TBX22 variant, and therefore the upper limb anomalies in the patient could be unrelated or limb anomalies may have been unascertained in previous patients.

Created: 11 Oct 2018, 9:40 a.m.