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References OMIM Gene GeneReviews HGMD HGNC
last update : 19/03/07
Symbol DEL7Q21
Location 7q21.3
Name chromosome 7q21 interstitial deletion
Other name(s) monosomy 7q21
Corresponding gene SHFM1 , DLX5 , DLX6 , SGCE , KRIT1
Main clinical features
  • severe mental retardation, short stature, microcephaly
  • inconstant limb abnormalities (split hand/split foot malformation)
  • hearing loss in about one-third of these patients and genito-urinary abnormalities in some
  • variable size and gene content may sustain a different phenotype
  • Genetic determination chromosomal
    Related entries SHFM1
    Function/system disorder multisystem/generalized
    mental retardation
    Type MCA/MR
    Gene mutationChromosome rearrangementEffectComments
      breakpoint   translocation or inversion with a breakpoint at 7q21.3
      deletion   interstitial, variable size with a ~1.2 Mb critical region containing the DLX5, DLX6 and DSS1 candidate genes
      deletion   ranging in size from 1.63 to 8.78 Mb encompassing up to 43 genes among which SGCE, KRIT, COL1A2 with/without SHFM1D, DLX5 and DLX6 ; gene content determines the clinical phenotype
    Genotype/Phenotype correlations ~30 percent of obligate carriers show no phenotypic abnormalities ; patients with paternal deletion encompassing the maternally imprinted gene SGCE have a myoclonus-dystonia plus syndrome (see DYT11) ; some deletions may include the KRIT gene, which is a major cause of cavernous cerebral malformations type I ; hearing loss, craniofacial defects, and an inv(7)(q21.3q35) with a 5 bp deletion at the 7q21.3 breakpoint that could contain regulatory elements necessary for DLX5 and DLX6 expression