A new family with an SLC9A6 mutation expanding the phenotypic spectrum of Christianson syndrome.
Fiche publication
Date publication
août 2016
Journal
American journal of medical genetics. Part A
Auteurs
Membres identifiés du Cancéropôle Est :
Pr HUET Frédéric, Pr MANDEL Jean-Louis, Pr FAIVRE Laurence, Pr KUENTZ Paul
Tous les auteurs :
Masurel-Paulet A, Piton A, Chancenotte S, Redin C, Thauvin-Robinet C, Henrenger Y, Minot D, Creppy A, Ruffier-Bourdet M, Thevenon J, Kuentz P, Lehalle D, Curie A, Blanchard G, Ghosn E, Bonnet M, Archimbaud-Devilliers M, Huet F, Perret O, Philip N, Mandel JL, Faivre L
Lien Pubmed
Résumé
Using targeted next generation sequencing, we have identified a splicing mutation (c.526-9_526-5del) in the SLC9A6 gene in a 9-year-old boy with mild intellectual disability (ID), microcephaly, and social interaction disabilities. This intronic microdeletion leads to the skipping of exon 3 and to an in-frame deletion of 26 amino acids in the TM4 domain. It segregates with cognitive impairment or learning difficulties in other members of the family. Mutations in SLC9A6 have been reported in X-linked Christianson syndrome associating severe to profound intellectual deficiency and an Angelman-like phenotype with microcephaly, absent speech, ataxia with progressive cerebellar atrophy, ophthalmoplegia, epilepsy, and neurological regression. The proband and his maternal uncle both have an attenuated phenotype with mild ID, attention deficit disorder, speech difficulties, and mild asymptomatic cerebellar atrophy. The proband also have microcephaly. The mutation cosegregated with learning disabilities and speech difficulties in the female carriers (mother and three sisters of the proband). Detailed neuropsychological, speech, and occupational therapy investigations in the female carriers revealed impaired oral and written language acquisition, with dissociation between verbal and performance IQ. An abnormal phenotype, ranging from learning disability with predominant speech difficulties to mild intellectual deficiency, has been described previously in a large proportion of female carriers. Besides broadening the clinical spectrum of SLC9A6 gene mutations, we present an example of a monogenic origin of mild learning disability. © 2016 Wiley Periodicals, Inc.
Référence
Am. J. Med. Genet. A. 2016 Aug;170(8):2103-10