EPHA7 gene located at 6q16.1 is associated with a neurodevelopmental disorder
The ephrin receptor A7 (EPHA7) is one of the genes involved in the formation of dendrites during brain development. This gene is located at 6q16.1. Only one child with a deletion of this gene has been reported so far. The authors describe 12 new patients with deletions of 6q16.1 involving the EPHA7 gene. Deletion sizes were from 0.152 Mb to 6.4 Mb. In four patients the EPHA7 was the only deleted gene, 8 others had associated deletions of other neighboring genes. The ages of the patients varied from 15 months to 11 years. One boy also had an additional deletion of 7q11.23, causing Williams syndrome. All patients with the EPHA7 deletion revealed developmental delay. They started talking between 24 and 42 months. Behavioral problems (hyperactivity, hyperkinesia, attention deficit disorder) were found in all studied children. Half of the patients revealed a sleep disturbance. Microcephaly was found in 5/13 patients (including a previously reported boy), although only one of them had microcephaly at birth. Mild dysmorphic features were reported in 7/13 patients, but these features did not produce a recognizable pattern. Four children (including one with associated Williams syndrome) had congenital heart defects. The parents of 2 children could not be examined. Among 10 other patients in the studied group only one (having the largest 6.4 Mb loss) had a sporadic deletion. Nine other children inherited their deletions from their parents: 4 from the healthy mothers and 5 from the fathers (including a family where a mildly affected father had 4 affected kids). The possibility of inheritance from an unaffected parent shows that haploinsufficiency of EPHA7 could act as a risk factor for developmental delay, although the expressivity of this deletion may be very variable and penetrance may be incomplete. Parents of children with deletions in this area should receive genetic counseling regarding further pregnancies.
Levy J. et al. “EPHA7 haploinsufficiency is associated with a neurodevelopmental disorder”. “Clin. Genet.” 2021, v. 100 (4), 396-404.
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