HPCA and Dystonia: By way of comparison, on the basis of the same datasets, 31 missense (11 of which are predicted to be damaging by both SIFT and PolyPhen-2), two splice-site, and one frameshift variant have been detected in LAPTM5. Although we cannot, because of a lack of data, be certain that this low level of variation in HPCA extends to all populations, this observation does at least further increase the likelihood that the identification of compound-heterozygous HPCA mutations segregating perfectly with disease in a second dystonia-affected kindred was very unlikely to have occurred by chance.