Mucolipidosis Type IV
Summary
Mucolipidosis type IV is a lysosomal storage disorder caused by deficiency of the mucolipin-1 channel, which is essential for normal lysosomal function. Without this channel, lipids and other materials accumulate in lysosomes throughout the body, particularly affecting the brain and eyes.
Practical takeaway
This matters when planning children, particularly if your partner is also of Ashkenazi Jewish descent. A carrier test can determine your partner's status. If both are carriers, a genetic counsellor can discuss the clinical spectrum and family planning options. Realised does not calculate reproductive risk or advise on reproductive decisions.
Evidence detail
What Carrier Status Means For You
You are not affected. One working copy of MCOLN1 produces sufficient mucolipin-1 for normal lysosomal function. Your carrier status becomes relevant if your partner also carries an MCOLN1 variant. In that case, each child has a 25% chance of being affected, 50% carrier, 25% unaffected.
Population Context
The IVS3-2A>G founder mutation gives Ashkenazi Jewish individuals a carrier frequency of approximately 1 in 100. Outside this population, mucolipidosis IV is extremely rare. Part of the expanded Ashkenazi Jewish carrier panel.
Limitations
23andMe tests 1 MCOLN1 variant. For Ashkenazi Jewish individuals, the IVS3-2A>G variant provides reasonable coverage. For non-Ashkenazi individuals, coverage is minimal. Comprehensive carrier screening through a clinical laboratory is recommended for broader variant detection.