Larger duplications in the same region have also been observed in association with mental retardation, and, in one case, the over-expression of ZNF81 has also been verified by mRNA quantification.
ZNF630 is a member of the primate-specific Xp11 zinc finger gene cluster that consists of six closely related genes, of which ZNF41, ZNF81, and ZNF674 have been shown to be involved in mental retardation.
Interestingly, mutations in all four genes (KDM5C, ARX, ZNF711 and PHF8) are associated with X-linked NDDs comprising intellectual disability as a core feature. in vitro analysis of the KDM5C promoter revealed that ARX and ZNF711 function as antagonist transcription factors that activate KDM5C expression and compete for the recruitment of PHF8.
Patients with mutations in ZNF711 all present with mild to moderate ID and poor speech accompanied by additional features in some patients, including autistic features and mild facial dysmorphisms, suggesting that ZNF711 mutations cause non-syndromic ID.
ZNF630 is a member of the primate-specific Xp11 zinc finger gene cluster that consists of six closely related genes, of which ZNF41, ZNF81, and ZNF674 have been shown to be involved in mental retardation.
Multiplex XLMR pedigrees have been reported with only one mutated patient having autism and MR: different X-located MR genes have been shown to be involved (NLGN4, MECP2, OPHN1, ZNF674 and FRAXA) which does not suggest that they could be "autism genes".
CAMOS (Cerebellar Ataxia with Mental retardation, Optic atrophy and Skin abnormalities) is a rare autosomal recessive syndrome characterized by a nonprogressive congenital cerebellar ataxia associated with mental retardation, optic atrophy, and skin abnormalities.
ZNF589 belongs to KRAB-domain zinc-finger proteins previously implicated in ID, HHAT is predicted to affect sonic hedgehog, which is involved in several disorders with ID, KMT2B associated with syndromic ID fits the epigenetic module underlying the Kleefstra syndromic spectrum.
We found that DNA methylation at birth differentiated ADHD trajectories across multiple genomic locations, including probes annotated to SKI (involved in neural tube development), ZNF544 (previously implicated in ADHD), ST3GAL3 (linked to intellectual disability) and PEX2 (related to perixosomal processes).
Wild-type ZNF41 contains a highly conserved transcriptional repressor domain that is linked to mechanisms of chromatin remodeling, a process that is defective in various other forms of MR. Our results suggest that ZNF41 is critical for cognitive development; further studies aim to elucidate the specific mechanisms by which ZNF41 alterations lead to MR.
Based on our results, ZNF533 is the only gene contained in the overlapping region with other deletions at 2q31.2, and it is most probably the fourth zinc-finger gene implied in mental retardation.