Compound heterozygous mutations in the ALDH3A2 gene cause Sjögren-Larsson syndrome: a case report.

Purpose: Sjögren-Larsson syndrome is a rare, autosomal, recessive neurocutaneous disorder caused by mutations in the ALDH3A2 gene, which encodes the fatty aldehyde dehydrogenase enzyme. Deficiency in fatty aldehyde dehydrogenase results in an abnormal accumulation of toxic fatty aldehydes in the brain and skin, which cause spasticity, intellectual disability, ichthyosis, and other clinical manifestations. We present the clinical features and mutation analyses of a case of SLS.Materials and Methods: The family history and clinical data of the patient were collected. Genomic DNA was extracted from peripheral blood samples of the patient and her parents, and next-generation sequencing was performed. The candidate mutation sites that required further validation were then sequenced by Sanger sequencing. Bioinformatics software PSIPRED and RaptorX were used to predict the secondary and tertiary structures of proteins.Results: The patient, a five-year-old girl with complaints of cough for three days and intermittent convulsions for seven hours, was admitted to the hospital. Other clinical manifestations included spastic paraplegia, mental retardation, tooth defects, and ichthyosis. Brain magnetic resonance imaging showed periventricular leukomalacia. Genetic screening revealed compound heterozygous mutations in the ALDH3A2 gene: a frameshift mutation c.779delA (p.K260Rfs*6) and a missense mutation c.1157A > G (p.N386S). Neither of the ALDH3A2 alleles in the compound heterozygote patient were able to generate normal fatty aldehyde dehydrogenase, which were likely responsible for her phenotype of Sjögren-Larsson syndrome.Conclusion: The compound heterozygous mutations found in the ALDH3A2 gene support the diagnosis of Sjögren-Larsson syndrome in the patient and expand the genotype spectrum of the gene.

Oral sugar clearance and other caries-related factors of stimulated whole saliva in patients with secondary Sjögren syndrome.

OBJECTIVE: To compare oral sugar clearance, salivary flow rate, buffer capacity, salivary counts of mutans streptococci and lactobacilli in whole saliva, and root caries in subjects with secondary Sjögren syndrome with those of healthy subjects. METHOD AND MATERIALS: Twenty subjects with secondary Sjögren syndrome and 20 healthy subjects (age 30 to 55 years; all women) rinsed their mouth with a 20% sucrose solution. Before the rinse and 2, 5, 10, and 30 minutes after the rinse, 2 paper disks were soaked with saliva, 1 under the tongue and 1 in the mandibular vestibule. The salivary sucrose concentration was determined enzymatically. The clearance time and the area under the sugar clearance curve (AUC) were calculated. RESULTS: Patients with secondary Sjögren syndrome and with low salivary flow had longer sugar clearance times in the mandibular buccal vestibule and sublingual regions than did healthy individuals (P = .000 and P = .000, respectively). Significant differences of AUC values between the groups for the buccal and sublingual regions were also found (P = .000 and P = .003, respectively). CONCLUSION: Subjects with secondary Sjögren syndrome had longer sugar clearance time, related to low salivary flow, high counts of cariogenic microorganisms, and decayed and filled surfaces in the root.