ML4 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 ML4. 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 ML4, 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 ML4 when both parents carry the defective ML4 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 ML4 with a simple blood test.
  • If both parents are found to be carriers of ML4, 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 ML4.
  • If already pregnant, and both parents have been identified as ML4 carriers, amniocentesis or chorionic villus sampling (CVS) can be performed. This is usually performed at approximately 10-14 weeks gestation.
  • ML4 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).