Recovered insulin production after thiamine administration in permanent neonatal diabetes mellitus with a novel solute carrier family 19 member 2 (SLC19A2) mutation

Abstract

Background: Solute carrier family 19 member 2 (SLC19A2) gene deficiency is one of the causes of permanent neonatal diabetes mellitus (PNDM) and can be effectively managed by thiamine supplementation. Herein we report on a male patient with a novel SLC19A2 mutation and summarize the clinical characteristics of patients with SLC19A2 deficiency. Methods: The genetic diagnosis of the patient with PNDM was made by sequencing and quantitative polymerase chain reaction. The clinical characteristics of PNDM were summarized on the basis of a systematic review of the literature. Results: The patient with PNDM had c.848G>A (p.W283X) homozygous mutation in SLC19A2. His father had a wild-type SLC19A2 (c.848G) and his mother was c.848G/A heterozygous. The patient and his father both had a diploid genotype (c.848A/A and c.848G/G). After oral thiamine administration, the patient's fasting C-peptide levels increased gradually, and there was a marked decrease in insulin requirements. A search of the literature revealed that thiamine treatment was effective and improved diabetes in 63% of patients with SLC19A2 deficiency. Conclusions: A novel SLC19A2 mutation (c.848G>A; p.W283X) was identified, which was most likely inherited as segmental uniparental isodisomy. Insulin insufficiency in PNDM caused by SLC19A2 deficiency can be corrected by thiamine supplementation. The differential diagnosis of SLC19A2 deficiency should be considered in children with PNDM accompanied by anemia or hearing defects to allow for early treatment.

The Roles of Solute Carriers in Auditory Function

“…SLC19 is a folate/thiamine transporter family, and there are three members (SLC19A1-3), of which SLC19A1 transports folates but not thiamine, and the other two transport thiamine but not folates (Zhao and Goldman, 2013). Mutations in the SLC19A2 gene, encoding thiamine transporter 1 (THTR1), were reported to be associated with thiamine-responsive megaloblastic anemia (TRMA) (Scharfe et al, 2000;Ozdemir et al, 2002;Ghaemi et al, 2013;Setoodeh et al, 2013;Sun et al, 2018;Amr et al, 2019), which is characterized by early-onset diabetes mellitus, anemia, and sensorineural deafness.…”

Congenital Diabetes: Comprehensive Genetic Testing Allows for Improved Diagnosis and Treatment of Diabetes and Other Associated Features

“…Both the anemia and the diabetes may be responsive to thiamine treatment. A recent case study of a patient with a novel SLC19A2 mutation reported an increase in fasting C-peptide levels after 3 months of thiamine treatment and a subsequent decrease in insulin requirements [92]. By 23 months old, after 11 months of thiamine treatment, the patient’s C-peptide had increased by 0.24 ng/mL, and the patient no longer required insulin treatment.…”