Hamzeh AR, Nair P, Mohamed M, Saif F, Tawfiq N, Al-Ali MT, Bastaki F. A novel missense mutation in ATRX uncovered in a Yemeni family leads to alpha-thalassemia/mental retardation syndrome without alpha-thalassemia.
Ir J Med Sci 2016;
186:333-337. [PMID:
26860117 DOI:
10.1007/s11845-016-1418-6]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 01/31/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND
Intellectual disability (ID) features in numerous heritable medical conditions that result from ATRX mutations. Alpha-thalassemia mental retardation syndrome (ATR-X syndrome) is the most notable manifestation of ATRX dysfunction. In addition to ID, genitourinary and craniofacial abnormalities are regularly observed with or without alpha-thalassemia.
AIMS
The study sought to characterize two cases of ATR-X in a Yemeni family clinically and molecularly.
METHODS
PCR amplification and Sanger sequencing were used to study the ATRX gene in a Yemeni family. Also, methylation-sensitive PCR was used to perform X-inactivation studies. CADD, SNAP2 and PolyPhen-2 helped to predict the functional consequences of the variant.
RESULTS
Molecular testing revealed a novel hemizygous missense mutation (c.5666T>G) in the ATRX gene in the two Yemeni brothers. This mutation was found in a heterozygous state in the mother, with the chromosome harboring the mutated allele being under strongly skewed X-inactivation.
CONCLUSIONS
The mutated gene is predicted to have a disrupted SNF-2 domain at a conserved residue; p.Leu1889Trp, which is deemed functionally damaging. This report offers, for the first time, full clinical and molecular characterization of a novel ATRX variant in an Arab family.
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