RESUMO
BACKGROUND: Loss of function variants and whole gene deletions of ZNF462 has been associated with a novel phenotype of developmental delay/intellectual disability and distinctive facial features. Over two dozen cases have been reported to date and the condition is now known as Weiss-Kruszka syndrome (OMIM# 618619). There are several older reports in the literature and DECIPER detailing individuals with interstitial deletions of 9q31 involving the ZNF462 gene. Many of the characteristic facial features described in these microdeletion cases are similar to those who have been diagnosed with Weiss-Kruszka syndrome. METHODS: We describe three additional patients with overlapping 9q31 deletions and compare the phenotypes of the microdeletion cases reported in the literature to Weiss-Kruszka syndrome. RESULTS: Phenotypic overlap was observed between patients with 9q31 deletions and Weiss-Kruszka syndrome. Several additional features were noted in 9q31 deletion patients, including hearing loss, small head circumference, palate abnormalities and short stature. CONCLUSIONS: The common region of overlap of microdeletion cases implicates ZNF462 as the main driver of the recognizable 9q31 microdeletion phenotype. The observation of additional features in patients with 9q31 microdeletions that are not reported in Weiss-Kruszka syndrome further suggests that other genes from the 9q31 region likely act synergistically with ZNF462 to affect phenotypic expression.
Assuntos
Anormalidades Múltiplas , Deleção Cromossômica , Humanos , Síndrome , Fenótipo , Estruturas Cromossômicas , Anormalidades Múltiplas/genética , Proteínas de Ligação a DNA/genética , Proteínas do Tecido Nervoso/genética , Fatores de Transcrição/genéticaRESUMO
Duplications of 4q31-qter have been rarely documented; moreover, triplications at this chromosomal region have never been described. Here we report a family through two generations (mother and three sons) with triplication of 4q32.1-q32.2. Their characteristic features include: macrocephaly, a long midface, hypoplastic zygoma, wide nasal bridge, short nose, downslanting and small palpebral fissures, and small, low-set and squared-off ears. Among the three sons, two had Hirschsprung disease, and one had constipation at birth. The phenotype of triplication of 4q32.1-q32.2 appeared to be distinct from duplications of 4q31-qter.
