A new frame shift pathogenic variant (c.773dupT) in the BCKDHB gene caused MSUD in an infant from north of Iran
Year: 2026
Type: article
Study design: Case Report
Abstract: Objectives Inborn errors of metabolism (IEMs) result from pathogenic variants in genes involved in essential metabolic pathways. Newborn screening (NBS) using tandem mass spectrometry (MS/MS) has facilitated the early detection and diagnosis of IEMs, enabling timely medical intervention and improved clinical outcomes. This study introduces a novel pathogenic variant in the BCKDHB gene in a case of maple syrup urine disease (MSUD) diagnosed through the NBS program in northern Iran. Case presentation Dried blood spot samples from newborns were analyzed using MS/MS (Shimadzu LCMS-8045, Japan), which identified a consanguineous case suspected of having MSUD. The confirmatory HPLC test revealed elevated levels of threonine, valine, isoleucine, and allo-isoleucine, indicating MSUD. Genetic analysis identified a homozygous frameshift variant, c.773dupT (NM_183050.4, p.Leu260ThrfsTer12), in exon 7 of the BCKDHB gene. Conclusions The identification of novel pathogenic variants in MSUD patients, along with phenotype-genotype correlations, may predict the clinical severity of the variant and offer prognostic value, particularly for individuals with this specific variant.
Institution: Mazandaran University of Medical Sciences
Language: English
Subfield: Clinical Biochemistry
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $565
OpenAlex ID: W7164911368