Mucolipidosis IV – ML IV

For more information please download our Guide to ML IV.

What is Mucolipidosis IV?

Mucolipidosis IV (ML IV) is a rare genetic disorder belonging to a group of disorders known as the lysosomal disorders. It is most commonly seen in Jews of Eastern European background. Other names for this condition include Ganglioside Sialidase Deficiency and Sialolipidosis.

What causes ML IV?

ML IV is a rare inherited metabolic disorder believed to be caused by alterations in a membrane protein due to mutations in the mucolipin-1 gene. This results in the blockage of endocytic transport which is the absorption of materials, for example, into the cell. This prevents the lysosomes forming correctly which results in a storage of complex lipids within the lysosome. This can cause iron deficiency anaemia and the neurodegenerative features seen in ML IV

How is ML IV inherited?

ML IV is an autosomal recessive disease; both parents must carry the same defective gene and each pass this same defective gene to their child. Where both parents are carriers of the ML IV gene there is a 25% (1:4) chance of having an affected child with each pregnancy. There is a 50% (1:2) chance of a child receiving only one copy of the defective gene and therefore being a carrier.

A carrier will not be affected but can pass the defective gene to his/her offspring. The remaining 25% (1:4) will be neither affected nor a carrier. Using information from an affected individual’s DNA, it may be possible to determine whether brothers and sisters are carriers of, or affected by, ML IV.  For further information on the inheritance pattern of MPS and Related Diseases contact the MPS Society for a specialist booklet on inheritance