Clinical and Molecular Spectrum of 1q21.1 Copy Number Variations: A Case Series.
5 affiliations
- 1Department of Medical Genetics, University of Health Sciences Basaksehir Cam and Sakura City Hospital, Istanbul 34460, Turkey.
- 2Department of Pediatric Genetics, University of Health Sciences Basaksehir Cam and Sakura City Hospital, Istanbul 34480, Turkey.
- 3Nevagen Genetic Diagnosis Center, Istanbul 34010, Turkey.
- 4Department of Molecular Biology and Genetics, Faculty of Engineering and Natural Sciences, Biruni University, Istanbul 34460, Turkey.
- 5Department of Molecular Biology and Genetics, Faculty of Engineering and Natural Sciences, Istanbul Atlas University, Istanbul 34203, Turkey.
Abstract
Background
1q21.1 copy number variations (CNVs) are recurrent rearrangements with a clinical spectrum, from neurodevelopmental disorders and congenital anomalies to apparently unaffected carrier status, reflecting incomplete penetrance and variable expressivity.Methods
Our chromosomal microarray (CytoScan HD) database was retrospectively screened for pathogenic or likely pathogenic 1q21.1 CNVs.Results
Twenty probands from 19 families (14 postnatal, 6 prenatal) carried 21 CNV events: 11 deletions (52.4%) and 10 duplications (47.6%). Of these, 16 (76.2%) were confined to the distal segment, 3 (14.3%) to the proximal segment, and 2 (9.5%) spanned both. One proband carried coexisting proximal duplication and distal deletion, both inherited from an apparently unaffected father. Of the 17 probands (85%) with parental testing, 7 (41.2%) had de novo and 10 (58.8%) inherited CNVs. Distal CNVs were mostly observed in probands with neurodevelopmental or cardiac phenotypes, whereas bilateral upper extremity anomalies were observed in both prenatally ascertained fetuses with isolated proximal deletions. Corpus callosum atrophy and choanal atresia were infrequently reported co-occurring findings, whereas prenatal intracranial hemorrhage was potentially novel; each occurred in one proband. Given the small proximal subgroup and differing ascertainment, these segment-associated trends are descriptive.Conclusions
This series highlights the relevance of segment localization and parental segregation data in interpreting 1q21.1 CNVs.
Related
- Association of Copy Number Variations in PTEN with Autism Spectrum Disorder
- Expanding the Clinical and Molecular Spectrum of Cartilage-Hair Hypoplasia in the Mexican Population
- Comprehensive Clinical, Neuroradiologic, and Oral Health of 23 Individuals With MOPDII: Molecular Spectrum and Phenotypic Features.
- Genetic Insights into the Comorbidity of Congenital Heart Disease and Neurodevelopmental Disorders: Focus on Copy Number Variations.
- Dose-dependent myelin g-ratio alterations in the white matter of 16p11.2 copy number variations
BibTeX
@article{esen2026clinical,
title = {{Clinical and Molecular Spectrum of 1q21.1 Copy Number Variations: A Case Series.}},
author = {Tuna Eren Esen and Lale Yilmaz Celik and Aydeniz Aydin Gumus and Pelin Ercoskun and Serdar Bozlak and Alper Gezdirici and Cuneyd Yavas and Ilknur Yilmaz},
journal = {Genes},
year = {2026},
month = oct,
doi = {10.3390/genes17101284},
url = {https://europepmc.org/article/MED/42938400},
note = {CC BY},
}
RIS
TY - JOUR
TI - Clinical and Molecular Spectrum of 1q21.1 Copy Number Variations: A Case Series.
AU - Tuna Eren Esen
AU - Lale Yilmaz Celik
AU - Aydeniz Aydin Gumus
AU - Pelin Ercoskun
AU - Serdar Bozlak
AU - Alper Gezdirici
AU - Cuneyd Yavas
AU - Ilknur Yilmaz
PY - 2026
DA - 2026/10/15
JO - Genes
DO - 10.3390/genes17101284
UR - https://europepmc.org/article/MED/42938400
AB - Background 1q21.1 copy number variations (CNVs) are recurrent rearrangements with a clinical spectrum, from neurodevelopmental disorders and congenital anomalies to apparently unaffected carrier status, reflecting incomplete penetrance and variable expressivity.Methods Our chromosomal microarray (CytoScan HD) database was retrospectively screened for pathogenic or likely pathogenic 1q21.1 CNVs.Results Twenty probands from 19 families (14 postnatal, 6 prenatal) carried 21 CNV events: 11 deletions (52.4%) and 10 duplications (47.6%). Of these, 16 (76.2%) were confined to the distal segment, 3 (14.3%) to the proximal segment, and 2 (9.5%) spanned both. One proband carried coexisting proximal duplication and distal deletion, both inherited from an apparently unaffected father. Of the 17 probands (85%) with parental testing, 7 (41.2%) had de novo and 10 (58.8%) inherited CNVs. Distal CNVs were mostly observed in probands with neurodevelopmental or cardiac phenotypes, whereas bilateral upper extremity anomalies were observed in both prenatally ascertained fetuses with isolated proximal deletions. Corpus callosum atrophy and choanal atresia were infrequently reported co-occurring findings, whereas prenatal intracranial hemorrhage was potentially novel; each occurred in one proband. Given the small proximal subgroup and differing ascertainment, these segment-associated trends are descriptive.Conclusions This series highlights the relevance of segment localization and parental segregation data in interpreting 1q21.1 CNVs.
SN - 2073-4425
ER -