Response to restrictive dermopathy and ZMPSTE24 mutations in Mennonites: Evidence for allelic heterogeneity^†

To the Editor:

In 2005, Dr. Miner's group [Moulson et al., 2005] described several cases of restrictive dermopathy, including a kindred of Mennonite origin with a novel c.54dupT mutation in the ZMPSTE24 gene. I thank Dr. Miner for pointing out an error in my article [Li, 2010] in which I reported a homozygous mutation of c.1085dupT in a Mennonite baby. The sentence “I posit this to be the first mutation documented in people of Mennonite origin” in the last paragraph should have been “I posit this to be the first time this mutation has been documented in people of Mennonite origin.”

The mutation c.1085dupT is the most commonly reported to date and has been shown to present in people of Dutch and German background, but it remains to be seen whether the Mennonite mutation is on the same haplotype as non-Mennonites of European extraction. It is also interesting to note that for a very rare genetic condition, two mutations have now been documented in Mennonites and that the affected, although very small in number, were all homozygous and their parents [Moulson et al., 2005] and living relative [Miner, 2010] carried the same mutations. These two mutations, c.54dupT and c.1085dupT, have not been noted in the same family in this population to date.