We observed a CHARGE syndrome patient with chromodomain helicase DNA-binding protein 7 mutation showing DiGeorge sequence including the defect of T cells accompanied with the aplasia of the thymus, severe hypoparathyroidism, and conotruncal cardiac anomaly.
A unifying hypothesis that could explain both the DiGeorge syndrome phenotype and the Kallman syndrome phenotype in patients with CHARGE syndrome may be that the mutation in CHD7 is likely to exert its effect in the common branch of the two pathways of neural crest cells.
The most commonly observed recurrent CNVs were NPHP1 duplications (233), CHRNA7 duplications (175), and 22q11.21 deletions (DiGeorge/velocardiofacial syndrome, 166).
The mitochondrial citrate transporter gene, SLC25A1 or CIC, maps on chromosome 22q11.21, a region amplified in some tumors and deleted in developmental disorders known as velo-cardio-facial- and DiGeorge syndromes.
A recent study in a small sample of patients with velo-cardio-facial syndrome who had bipolar affective disorder suggested that the Met (low activity) COMT allele might be associated with rapid-cycling in this population.
Several lines of evidence have implicated the catechol-O-methyltransferase (COMT) gene as a candidate for schizophrenia (SZ) susceptibility, not only because it encodes a key dopamine catabolic enzyme but also because it maps to the velocardiofacial syndrome region of chromosome 22q11 which has long been associated with SZ predisposition.
A gender-moderated effect of a functional COMT polymorphism on prefrontal brain morphology and function in velo-cardio-facial syndrome (22q11.2 deletion syndrome).
A gender-moderated effect of a functional COMT polymorphism on prefrontal brain morphology and function in velo-cardio-facial syndrome (22q11.2 deletion syndrome).
Of special interest is the role of this gene in major psychoses especially since a microdeletion (22q11) containing the COMT gene (velo-cardio-facial syndrome) also carries with it several types of behavioral disorders, including an increased prevalence of schizophrenia.
The gene encoding catechol-O-methyltransferase (COMT) is a strong candidate for schizophrenia susceptibility, owing to the role of COMT in dopamine metabolism, and the location of the gene within the deleted region in velocardiofacial syndrome, a disorder associated with high rates of schizophrenia.
One of these is its biochemical function in metabolism of catecholamine neurotransmitters; another is the microdeletion, on chromosome 22q11, that includes the COMT gene and causes velocardiofacial syndrome, a syndrome associated with a high rate of psychosis, particularly schizophrenia.
These data suggest that the COMT gene does not play a major role in the pathogenesis of schizophrenia, and the genotypic overlap between schizophrenia and velocardiofacial syndrome was rare in this cohort.
Velocardiofacial syndrome is a genetic disorder associated with a microdeletion on the long arm of chromosome 22, and this segment is responsible for coding catechol-O-methyltransferase, an enzyme involved in dopamine degradation.
The gene for COMT is located on chromosome 22q11, an area that has been implicated in the pathogenesis of schizophrenia through linkage studies and through the detection of deletions in schizophrenics and velocardiofacial syndrome patients that often present psychotic symptomatology.
The prevalence of duplications and deletions of the 22q11.2 (DiGeorge syndrome) region was studied among babies born in Norway with open cleft palate without cleft lip (cleft palate only, CPO).