A genetic change in the NACC1 gene has recently been shown to cause a disorder that causes seizures, cataracts, feeding difficulties, microcephaly (small head size), extreme irritability/fussiness, failure to thrive, repetitive hand movements, and developmental delays and/or intellectual disability. All seven individuals described so far in medical journals have had the exact same genetic change, c.892C>T at the cDNA level and p.Arg298Trp at the protein level. The genetic change was new in the child (i.e. not inherited from a parent).
Individuals with a genetic change in the NACC1 gene other than the one that has been studied (c.892C>T/p.Arg298Trp variant) may cause less specific symptoms including developmental delay, intellectual disability, and/or autism, but more studies are needed in order to better understand these differences.