BTD Gene Mutations in Biotinidase Deficiency: Genotype-Phenotype Correlation

Area of Science:

• Genetics
• Biochemistry
• Medical Diagnostics

Background:

• Biotinidase deficiency is an inherited metabolic disorder.
• Newborn screening programs identify affected infants early.
• Understanding gene mutations is crucial for diagnosis and management.

Purpose of the Study:

• To identify mutations in the biotinidase (BTD) gene in a specific region.
• To correlate identified mutations with clinical presentations (phenotype-genotype correlation).

Main Methods:

• Descriptive study conducted between January 2018 and June 2020.
• Included 209 patients positive for biotinidase deficiency via newborn screening.
• Utilized next-generation DNA sequencing of BTD gene exons and mutation analysis software.

Main Results:

• Identified c.1330 G>C (p.D444H) as the most common mutation, followed by c.470 G>A (p.R157H).
• Most mutations were missense, predominantly in exon 4.
• D444H and R157H mutations were most frequent (66.66%) in symptomatic patients.

Conclusions:

• Common BTD gene mutations causing biotinidase deficiency were identified.
• Phenotype-genotype data association aids clinicians in genetic counseling and management.
• Findings support the implementation of prevention programs for inherited metabolic diseases.