Interstitial deletion of 7q22.1q31.1 in a boy with structural brain abnormality, cardiac defect, developmental delay, and dysmorphic features

Genome-Wide Homozygosity Mapping Reveals Genes Associated With Cognitive Ability in Children From Saudi Arabia

Recent studies of the genetic foundations of cognitive ability rely on large samples (in extreme, hundreds of thousands) of individuals from relatively outbred populations of mostly European ancestry. Hypothesizing that the genetic foundation of cognitive ability depends on the broader population-specific genetic context, we performed a genome-wide association study and homozygosity mapping of cognitive ability estimates obtained through latent variable modeling in a sample of 354 children from a consanguineous population of Saudi Arabia. Approximately half of the sample demonstrated significantly elevated homozygosity levels indicative of inbreeding, and among those with elevated levels, homozygosity was negatively associated with cognitive ability. Further homozygosity mapping identified a specific run, inclusive of the GRIA4 gene, that survived corrections for multiple testing for association with cognitive ability. The results suggest that in a consanguineous population, a notable proportion of the variance in cognitive ability in the normal range in children might be regulated by population-specific mechanisms such as patterns of elevated homozygosity. This observation has implications for the field's understanding of the etiological bases of intelligence and its variability around the world.

Interstitial deletion within 7q31.1q31.3 in a woman with mild intellectual disability and schizophrenia

We report the case of a Japanese woman with an interstitial deletion within the 7q31.1q31.3 region, she presented with mild intellectual disability since infancy, and later developed characteristic psychiatric manifestations, including abnormal behavior, delusions, and hallucinations. She was diagnosed with paranoid schizophrenia (F20.0, International Statistical Classification of Diseases and Related Health Problems 10th Revision). Array comparative genomic hybridization examination revealed the deletion involving several important genes for neurodevelopment. Particularly, FOXP2, DOCK4, MET, and WNT2 in this region are suggested to be related to language impairment, autistic disorders, and cognitive disorders, via the WNT pathway. In addition, the WNT signal pathway has been suggested to be implicated in the pathogenesis of psychiatric disorders such as schizophrenia and bipolar disorder. However, there is no case report regarding schizophrenia associated with a 7q31 microdeletion. We suspect that the disruptions of these one or plural genes among the interstitial deletion of 7q31.1q31.3 may be involved in the development of schizophrenia in this woman. This is the first report on schizophrenia associated with a 7q31 microdeletion.