Mutations in SLC4A4 have been reported in pedigrees with proximal renal tubular acidosis (pRTA) with HM and migraine (Demirci et al. 2006; Suzuki et al. 2010), but this gene was not considered in this study as none of the patients in our series showed renal abnormalities. This evidence concerns the gene SLC4A4 and proximal renal tubular acidosis.