Multi-year enzyme expression in patients with mucopolysaccharidosis type VI after liver-directed gene therapy.

Background: Mucopolysaccharidosis type VI (MPS VI) is due to a deficiency of the lysosomal enzyme arylsulfatase B (ARSB) that results in multi-organ accumulation of glycosaminoglycans (GAGs). Limitations of current treatments prompted the development of a liver-directed gene therapy clinical trial for MPS VI.

Methods: We report the long-term follow-up of patients with MPS VI who discontinued enzyme replacement therapy (ERT) and received a single intravenous infusion of high-dose (6 × 10 genome copies/kg) recombinant adeno-associated virus serotype 8 (AAV8) vector expressing ARSB under the control of a liver-specific promoter (ClinicalTrials.

Expanded Newborn Screening in Italy Using Tandem Mass Spectrometry: Two Years of National Experience.

Newborn screening (NBS) for inborn errors of metabolism is one of the most advanced tools for secondary prevention in medicine, as it allows early diagnosis and prompt treatment initiation. The expanded newborn screening was introduced in Italy between 2016 and 2017 (Law 167/2016; DM 13 October 2016; DPCM 12-1-2017). A total of 1,586,578 infants born in Italy were screened between January 2017 and December 2020.

Liver-Directed Adeno-Associated Virus-Mediated Gene Therapy for Mucopolysaccharidosis Type VI.

BACKGROUND: Mucopolysaccharidosis type VI (MPS VI) is an inherited multisystem lysosomal disorder due to arylsulfatase B (ARSB) deficiency that leads to widespread accumulation of glycosaminoglycans (GAG), which are excreted in increased amounts in urine. MPS VI is characterized by progressive dysostosis multiplex, connective tissue and cardiac involvement, and hepatosplenomegaly. Enzyme replacement therapy (ERT) is available but requires life-long and costly intravenous infusions; moreover, it has limited efficacy on diseased skeleton and cardiac valves, compromised pulmonary function, and corneal opacities.

High frequency of biotinidase deficiency in Italian population identified by newborn screening.

The biotinidase (BTD) enzyme is essential for recycling biotin, a water-soluble B-complex vitamin that is the coenzyme of four carboxylases involved in fatty acid synthesis, amino acid catabolism and gluconeogenesis. If untreated, total or partial BTD deficiencies lead to an autosomal recessive inherited organic aciduria whose clinical features, mainly presenting in the first years of life, include, seizures, skin rash, and alopecia. Based on residual BTD enzyme activity it is possible to identify partial or total biotinidase deficiency.