NEW YORK (Reuters Health) – Nonsyndromic clefts of the lip and/or palate are associated with alterations in brain structure, particularly on the left side, report investigators from the University of Iowa in Iowa City. These alterations appear to cause cognitive dysfunction.
As reported in the January/February issue of Genetics in Medicine, 46 adult men with nonsyndromic facial clefts and 46 male control subjects underwent MRI to evaluate brain volume and tissue composition.
Dr. Peg Nopoulos and colleagues observed that the volume of the anterior portion of the cerebrum was enlarged in men with clefting, adjusted mean 738 cc versus 709 cc (p = 0.0005), primarily due to an increase in cortical gray matter. The authors noted that the increased size of the cerebrum was pathologic in that it was inversely associated with Full Scale IQ.
The posterior cerebrum and cerebellum were decreased in volume. Those with clefting also exhibited decreases in cerebrospinal fluid.
The left temporal lobe was most affected (p < 0.0001), with decrements in volume of both gray and white matter. The Iowan team notes that that language is predominantly represented and processed by the left temporal lobe, especially in men. The subjects had mildly decreased IQ compared with control subjects, as well as specific deficits in language function.