Causing a developmental disorder
By whole-exome and whole-genome sequencing evidence has been found that MMP21 gene mutations may cause an autosomal recessively inherited form of heterotaxy. Heterotaxy (or heterotaxia) is an abnormal positioning of the thoracic and/or abdominal organs reversing left/right with respect to normal. The incidence is approximately 1/15,000. Mutations in several other genes and all kinds of inheritance (autosomal dominant, recessive, X-linked) have been so far reported. Matrix metalloproteinases, such as MMP21, are proteolytic enzymes that degrade the extracellular matrix proteins. The MMP21 gene contains 7 exons and spans about 10 kb. Thus far, no other genetic disorder has been associated to MMP21 mutations.
The new panel at Breda Genetics
Following this new evidence, Breda Genetics has updated its panel adding the MMP21 gene:
Heterotaxy, visceral, Tetralogy of Fallot, VATER & VACTERL(X) associations (ACVR2B, CFC1, CRELD1, GJA1, GDF1, FOXH1, LEFTY2, MMP21, NKX2-5, NODAL, ZIC3)
References: PMID: 26437028, OMIM: 608416.
Useful links: www.heterotaxy.org