Profound biotinidase deficiencyadmin
Profound biotinidase deficiency caused by (D444H) resulting in recurrent early childhood death in a Sudanese Family
Authors and Affiliations
Reem Salaheldin, Rayan Ali, Muntaser E Ibrahim, Imad Fadel-Elmula.
Biotinidase deficiency (BTD) is an autosomal recessive disease in which biotin recycling from biocytin or biotinylated peptides is impaired. The disorder is caused by absent or markedly deficient activity of biotinidase.
Material and methods
Two healthy parents presented with history of two daughters who had neurological cutaneous and respiratory manifestations who died at early childhood. They also had two healthy living daughters (8;4 year-old). Whole exom sequencing was done for the mother and then specific BTD gene sequencing was done for the father which were analyzed through bioinformatic tools.
Results: whole exom sequencing analysis of the mother genomic DNA showed heterozygous missense mutation in BTD gene with rs 13078881 was found. Identical mutation was latter identified also in the father DNA.
Discussion: This present mutation behaved in unusual way since it caused profound biotinidase deficency in homozygous state. According to our knowledge this the first ever case with profound biotinidase deficency in homozygous state to be reported.
Conclusion: In the absence of neonatal screening programmes whole genome sequencing remain the only effective way of diagnosis metabolic Mendelian disorders in underdeveloped countries.