Analysis of clinical phenotype and genotype of cerebral dysgenesis, neuropathy, ichthyosis, and palmoplantar keratoderma syndrome caused by a novel variant of SNAP29 gene / 中华神经科杂志

ABSTRACT

Objective:To investigate the clinial phenotype and genetic characteristics of a child with cerebral dysgenesis, neuropathy, ichthyosis, and palmoplantar keratoderma (CEDNIK) syndrome and to improve the clinicians′ understanding of this disease.Methods:Clinical data of the child with CEDNIK syndrome diagnosed in Department of Endocrinology, Genetics and Metabolism, Xi′an Children′s Hospital in June 2020 were collected. Whole exome sequencing was carried out to identify the potential variants of SNAP29 gene. Suspected variants were verified by Sanger sequencing of family numbers. The literature about the cases of CEDNIK syndrome were reviewed.Results:The proband is a boy, who was aged 1 year and 4 months, had the manifestations of psychomotor retardation, microcephaly, feeding difficulties, severe malnutrition, recurrent respiratory tract infection, binocular esotropia, sensorineural deafness, cutaneous ichthyosis and keratosis, left cryptorchidism. Brain magnetic resonance imaging indicated congenital dysplasia. Whole exome sequencing identified a homozygous variant of c.383dupT (p.E129Rfs *5) in the SNAP29 gene of the proband, and the heterozygous variation was observed at the same locus in his parents, which conformed to the autosomal recessive inheritance. This mutataion was determined as a pathogenic mutation according to the guidelines of American College of Medical Genetics and Genomics. Literature retrieval showed currently a total of 29 cases of CEDNIK syndrome were reported, containing 8 types of SNAP29 gene mutation. However, there was no Chinese case reported. And the c.383dupT (p.E129Rfs *5) mutation found in this study was a novel one which had not been reported yet. Conclusion:The phenotype of the proband is generally consistent with the CEDNIK syndrome and the novel c.383dupT (p.E129Rfs *5) mutation of SNAP29 gene is the genetic cause.