AOCCN2017

Presentation information

Poster Presentation

[P2-136~192] Poster Presentation 2

Fri. May 12, 2017 10:00 AM - 3:40 PM Poster Room B (1F Argos F)

[P2-181] An interstitial deletion was identified in Xq22.1 in a male patient with severe developmental delay

Kentaro Shirai (Department of Pediatrics,Tsuchiura Kyodo hospital, Japan)

[Introduction] Xq22 region is important, because duplications of this region including PLP1 gene is responsible for X-linked recessive leukodystrophy (Pelizaeus-Merzbacher disease; PMD). In comparison with PLP1 duplications, deletions of this region are infrequent and smaller than duplications. These findings suggest that male patients with larger deletions involving PLP1 would be embryonic lethal.
[Case] A male patient is 1 year and 5 months old. He was born at 38 weeks of gestation to healthy and non-consanguineous parents. Just after birth, severe neurological impairment was noted. He is in bedridden, no head control, and no voluntary movement. Tracheostomy and tube feeding were necessary. Brain radiological imaging revealed severely reduced volume of the cerebrum. Chromosomal microarray testing revealed 1.4-Mb deletion at Xq22, which did not include PLP1. This deletion was de novo origin.
[Discussion] There is no report of the similar patient. Our previous research disclosed five female patients with Xq22 microdeletion. All of them showed severe intellectual disability, hypotonia and behavioral abnormalities, including poor eye contact and sleep disturbance. Through genotype-phenotype correlation analysis, the possible candidate region responsible for such distinctive features has been narrowed down to the proximal or distal neighboring region for PLP1. The additional information provided by this study suggests the fact that proximal region from PLP1 is significantly important for neurological development, and the larger deletion of this region would be embryonic lethal for male patient.