A new 1p36.13‐1p36.12 microdeletion syndrome characterized by learning disability, behavioral abnormalities, and ptosis

Abstract

Two 1p36 contiguous gene deletion syndromes are known so far: the terminal 1p36 deletion syndrome and a 1p36 deletion syndrome with a critical region located more proximal at 1p36.23-1p36.22. We present even more proximally located overlapping deletions from seven individuals, with the smallest region of overlap comprising 1 Mb at 1p36. 13-1p36.12 (chr1:19077793-20081292 (GRCh37/hg19)) defining a new contiguous gene deletion syndrome. The characteristic features of this new syndrome are learning disability or mild intellectual disability, speech delay, behavioral abnormalities, and ptosis. The genes UBR4 and CAPZB are considered the most likely candidate genes for the features of this new syndrome. K E Y W O R D S behavioral abnormality, chromosome deletion, chromosomes, learning disability, human pair 1, ptosis

1p36 deletion syndrome: Review and mapping with further characterization of the phenotype, a new cohort of 86 patients

“…Recently, Nolting et al described “a new microdeletion syndrome at proximal 1p36 (1p36.13‐1p36.12)” in seven patients and determined a new SRO from 19,077,793 bp to 20,081,292 bp. These patients presented ID, speech delay, behavioral abnormalities, and congenital ptosis (Aagaard Nolting et al, 2020 ). Two patients in our cohort exhibit ptosis including one with a deletion (17175659‐22652664) encompassing the SRO described by Nolting.…”

Expanding the Etiology of Oculo–Auriculo–Vertebral Spectrum: A Novel Interstitial Microdeletion at 1p36

“…The most common manifestations were intellectual or learning disability and ptosis, which were both present in five out of seven patients. Other frequent features included epicanthus, thick eyebrows, high palate, protruding chin, misalignment of teeth, and heart malformations [28]. The SRO encompassed 1 Mb at Chr1:19077793-20081292).…”

Chromosome 1p36 Deletion Syndrome: Four Patients with Variable Presentations

“…Chromosome 1p36 deletion syndrome (OMIM #6078720) is considered a common subtelomeric microdeletion found in children, with an incidence of 1 in 5,000 to 1-10,000 individuals. 1,2 Distinctive craniofacial features include microbrachycephaly, prominent forehead, deep-set eyes, straight eyebrows, broad/flat nasal bridge, and midface hypoplasia, described both in earliest reported cases, as in large cohorts of individuals with 1p36 deletion syndrome. 3 Most of the patients with this chromosomal deletion have larger terminal deletions, or heterozygous deletion of the distal chromosomal band on the short arm of chromosome 1, whereas other rearrangements involving interstitial deletions or more complex rearrangements are less commonly seen.…”