A de novo 1.4-Mb Deletion at 21q22.11 in a Boy With Developmental Delay

作者：Fukai Ryoko; Hiraki Yoko; Nishimura Gen; Nakashima Mitsuko; Tsurusaki Yoshinori; Saitsu Hirotomo; Matsumoto Naomichi; Miyake Noriko^*

来源：American Journal of Medical Genetics, Part A, 2014, 164(4): 1021-1028.

DOI：10.1002/ajmg.a.36377

• 21q22
• 11 deletion
• developmental delay
• fluorescence in situ hybridization (FISH)
• copy number analysis
• ITSN1

Monosomy 21 is a very rare chromosomal abnormality. At least 45 patients with partial deletion involving 21q11 have been reported. Here, we report a Japanese boy who presented with pre- and postnatal growth delays, psychomotor developmental delay, microcephaly, and iris coloboma. Cytogenetic analysis revealed a de novo 1.4-Mb deletion at 21q22.11 containing 19 protein-coding RefSeq genes. We compared the clinical phenotypes between the present patient and 16 previously reported patients with a deleted region associated with postnatal growth delay and psychomotor developmental delay. Interestingly, ITSN1 was the only gene deleted or disrupted in all cases; this gene is known to be associated with intellectual disability. Microcephaly and brain structural abnormalities including polymicrogyria and agenesis/hypoplasia of the corpus callosum may also result from haploinsufficiency of ITSN1, highlighting its clinical significance for the neurological features of patients with monosomy 21.

• 出版日期2014-4