A new case of TAR syndrome confirms the importance of noncoding variants
in the etiopathogenesis of the disease.
Abstract
TAR syndrome is a rare congenital disorder whose genetic bases have
remained unclear for many years. It has now been understood that the
disease is caused by the compound inheritance of a rare null allele
(usually the 1q21.1 deletion) and a low-frequency hypomorphic noncoding
single nucleotide polymorphism (SNP) in RBM8A gene. Nevertheless, only a
limited set of variants has been identified so far. A recent report of
Boussion et al. described four novel RBM8A noncoding SNPs (i.e., 1)
c.205 + 3_205 + 6del, 2) c.206 − 13C>A, 3) c. −
19G>T, and 4) c.*6C>G) increasing the
mutational spectrum of TAR syndrome. Here, based on the recently
published manuscript by Boussion et al., we report data regarding an
additional African TAR patient carrying the 1q21.1q21.2 deletion in
trans with the 3’UTR (c.*6C>G) variant. Present data
further confirm the pathogenic role of this hypomorphic SNP and
highlights its relevance in the African population, leading to advice
geneticists to directly search for the c.*6C>G variant in
African patients affected by TAR syndrome and carrying the 1q21.1
deletion, shortening the diagnostic time window.