Chromosome band 7q21.3 harbors a locus for split hand/split foot malformation (SHFM1), and part of this locus, including the SHFM1 candidate genes SHFM1, DLX5, and DLX6, is deleted.
In addition, its removal by chromosomal abnormalities in humans could cause split hand and foot malformation 1 (SHFM1), a disorder associated with DLX5/6.
Mutations in the DLX5 gene have been linked to deficiencies in craniofacial and limb development in higher eukaryotes, including split hand and foot malformation 1 in humans.
Two of the patients presented with typical M-D, whereas one paediatric patient with split-hand/split-foot malformation and sensorineural hearing loss (SHFM1D, OMIM 220600) had not developed M-D at the age of 9 years.