Mirhosseini-Holmes-Walton syndrome clinically resembles Cohen syndrome, and whether these are clinically and genetically uniform entities has been disputed. These two disorders diverge considering the main clinical features only in respect to intermittent neutropenia, not reported in Mirhosseini-Holmes-Walton syndrome.
Horn et al. (2000) reported 2 brothers and a cousin from a multiply consanguineous kindred of Lebanese descent with a syndrome of microcephaly, progressive postnatal growth deficiency, mental retardation, hypotonia, chorioretinal dystrophy, and myopia. Homozygosity mapping localized the gene responsible for this condition to a 26.8-cM region on chromosome 8q21.3-q22.1 that overlaps the refined gene region for Cohen syndrome. The authors hypothesized that the syndrome in this family, Cohen syndrome, and Mirhosseini-Holmes-Walton syndrome may be allelic.