Deletions of the 1q telomere have been reported in several studies screening for subtelomeric rearrangements. However, an adequate clinical description is available from only a few patients. We provide a clinical description of a patient with a subtelomeric deletion of chromosome 1q, previously detected by us in a screening study. Comparison of the clinical presentation of our patient with rare cases reported previously provides further evidence for a specific phenotype of 1q patients, including mental retardation, growth retardation, sometimes with prenatal onset, progressive microcephaly, seizures, hand and foot abnormalities and a variety of midline defects, including corpus callosum, cardiac, genital and gastro-esophageal abnormalities. This clinical presentation is renmiscent of that of patients with larger, microscopically visible deletions of chromosome 1q (>3 Mb) characterized by growth and mental retardation, coarse faces with thin upper lip, epilepsy, and variable other anomalies. In addition, the breakpoint region was mapped to a 26 kb region within the RGS7 gene. Among the 17 known genes in the candidate region, are zinc-finger genes. Other members of this gene family have been implicated in different forms of mental retardation.

1q-syndrome, Mental retardation, Midline defects, Subtelomeric deletion, Zinc-finger genes,
American Journal of Medical Genetics. Part A
Department of Clinical Genetics

van Bever, Y, Rooms, L, Laridon, A, Reyniers, E, van Luijk, R, Scheers, S, … Kooy, R.F. (2005). Clinical report of a pure subtelomeric 1qter deletion in a boy with mental retardation and multiple anomalies adds further evidence for a specific phenotype. American Journal of Medical Genetics. Part A, 135 A(1), 91–95. doi:10.1002/ajmg.a.30695