MLIV is an autosomal recessive genetic disease, which means that it is genetically inherited through one’s parents, both of whom must be carriers of a defective gene, p19 which is responsible for MLIV. Mutated versions of that gene can be passed along to one’s children who become carriers of the mutation but who show no signs of the disease. In order for a child to be affected by MLIV, a child must receive a mutated copy of the gene from both the father and mother, as the diagram below shows. There is a 1 in 4 chance of having a child affected with MLIV when both parents carry the defective MLIV gene.

  • The optimal time for determination of genetic risk and clarification of carrier status is before pregnancy.
  • Prospective parents can be screened for being carriers of MLIV with a simple blood test.
  • If both parents are found to be carriers of MLIV, or any other genetic disease, they should consult a genetic counselor. The carrier rate in Jews of Eastern European descent is 1 in 100.
  • A genetic counselor can provide important information and support, which may be helpful in making family planning decisions.
  • Pre-implantation Genetic Diagnosis (PGD) maybe an option for prospective parents who are both carriers of MLIV.
  • If already pregnant, and both parents have been identified as MLIV carriers, amniocentesis or chorionic villus sampling (CVS) can be performed. This is usually performed at approximately 10-14 weeks gestation.
  • MLIV is an inherited autosomal recessive disease. If both parents are carriers, then each child has a 25% chance of inheriting the disease, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected (not even being a carrier).