Mucopolysaccharidoses (MPS) are a group of lysosomal storage disorders caused by the deficiency of specific enzymes which leads to the lysosomal accumulation of glycosaminoglycanes. Mucopolysaccharidosis type I or Hurler disease is characterized by the deficiency of alpha-l-iduronidase enzyme. Mucopolysaccharidosis type IVA or Morquio A disease is due to the lack of N-acetylgalactosamine-6-sulfate-sulfatase. Theses deficiencies result in a progressive accumulation of the substrates: dermatan and heparan sulfates for Mucopolysaccharidosis type I and keratan sulfate for MPS type IVA. This process leads to progressive and chronic course for visceral attacks of the affected organs such as lungs and heart. In the Hurler disease, the nervous system is particularly affected while in Morquio a disease, a skeletal dysplasia and a normal intelligence are characteristic.
Aim of the study: This study was carried out on MPS type I and MPS type IVA unrelated families recruited from many regions of Tunisia in order to determine the relation between consanguinity and these types of disorders.
Patients and methods: Clinical and molecular analyses confirmed the diagnosis for four MPS type I and five MPS type IVA studied families.
Results: First cousins unions characterize all families except one Hurler family and one Morquio A family where the consanguinity is third cousin degree.
Conclusion: MPS type I and type IVA seems to be associated with consanguinity in Tunisia.