Late Onset Subacute Profound Biotinidase Deficiency Caused by a Novel Homozygous Variant c.466-3T>G in the BTD Gene

Mohite, KaustubhNair, Karthik VijaySapare, AnilkumarBhat, VenkatramanShukla, AnjuKekatpure, MinalPatil, Siddaramappa J.2023-08-192023-08-192022-06Mohite Kaustubh, Nair Karthik Vijay, Sapare Anilkumar, Bhat Venkatraman, Shukla Anju, Kekatpure Minal, Patil Siddaramappa J.. Late Onset Subacute Profound Biotinidase Deficiency Caused by a Novel Homozygous Variant c.466-3T>G in the BTD Gene. Indian Journal of Pediatrics. 2022 Jun; 89(6): 594–5960973-76930019-5456http://imsear.searo.who.int/handle/123456789/223717Biotinidase defciency (BD) is an autosomal recessive disorder caused by bi-allelic mutation in the BTD gene. Clinical manifestations in BD mainly depends on residual biotinidase enzyme activity, although there are some exceptions. Broadly BD disorders are classifed as profound BD and partial BD. Further profound BD can be early onset, late onset, and sometimes may be asymptomatic. Clinically late-onset profound BD can present with spectrum of manifestations ranging from single organ to multiple organ involvement, typically afecting function of brain, eye, ear, and skin. Here, a frst-born child to consanguineous parents with late-onset profound BD presenting with hyperventilation secondary to lactic acidosis, hypotonia, evolving spasticity, and abnormal neuroimaging fndings caused by novel homozygous variant, c.466-3T>G in the BTD gene is reported.Biotinidase defciencyHyperventilationWeakened splice variant3-hydroxyisovalerateLactic acidosisLate Onset Subacute Profound Biotinidase Deficiency Caused by a Novel Homozygous Variant c.466-3T>G in the BTD GeneJournal ArticleIndiaDepartment of Pediatrics, Mazumdar Shaw Medical Center, Narayana Hrudayalaya Hospitals, Bangalore, Karnataka, IndiaDepartment of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, IndiaDepartment of Radiology, Mazumdar Shaw Medical Center, Narayana Hrudayalaya Hospitals, Bangalore, Karnataka, IndiaDepartment of Neurology, Division of Pediatric Neurology, Mazumdar Shaw Medical Center, Narayana Hrudayalaya Hospitals, Bangalore, Karnataka, IndiaDivision of Medical Genetics, Mazumdar Shaw Medical Center, Narayana Hrudayalaya Hospitals, Bangalore, Karnataka 560099, India