Retro-prospective, single-centre, observational study conducted at the Endocrine-Metabolic Diseases Center of the Pediatrics Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Italy.

The study involves children born in Emilia-Romagna region, Italy, from January 2016 to December 2020 with biotinidase deficiency identified through Neontal Screening at the Endocrine-Metabolic Diseases Center of the Pediatrics Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Italy. The primary aim of this study is to assess the incidence of biotinidase decificiency in this cohort of patients and the possible correlation between the genotype and the biochemical and clinical phenotype of this cohort of patients.

The study consists of the retrospective collection and analysis of clinical, biochemical and genetic data of pediatric patients who were taken in charge for Biotinidase Deficiency at the Endocrine-Metabolic Diseases Center of the Pediatrics Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Italy, following Neonatal Screening positivity.

For this cohort of patients, a clinical evaluation is planned annually after the diagnosis of Biotinidase Deficiency for the identification of possible long-term complications. A clinical follow-up of at least 36 months is expected.

According to clinical practice, parents of pediatric patients with Biotinidase Deficiency identified through Neonatal Screening will undergo molecular genetic analysis for specific familial mutations of the BTD gene, but will not be followed up.

INCLUSION CRITERIA:

FOR PEDIATRIC PATIENTS

• Neonatal Screening test result of Residual biotinidase Enzyme Activity <50% carried out from January 2016 to December 2019 at the Endocrine-Metabolic Diseases Center of the Pediatrics Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Italy;
• Neonatal Screening test result of Residual biotinidase Enzyme Activity <30% carried out from January 2020 to December 2020 at the Endocrine-Metabolic Diseases Center of the Pediatrics Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Italy;
• Obtaining informed consent from parents or legal guardian of pediatric patients.

FOR PARENTS

• Being a parent of a paediatric patient enrolled in the study;
• Availability of parental data;
• Obtaining informed consent.

EXCLUSION CRITERIA:

• Subjects with known chromosomal abnormalities or complex syndromes.

Pediatric patients with Biotinidase Deficiency (and their parents) identified through Neonatal Screening from January 2016 to December 2020 at the Endocrine-Metabolic Diseases Center of the Pediatrics Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Italy.