Identification of two novel heterozygous variants of SMC3 with Cornelia de Lange syndrome.
Mol Genet Genomic Med
; 12(5): e2447, 2024 May.
Article
en En
| MEDLINE
| ID: mdl-38733165
ABSTRACT
BACKGROUND:
Cornelia de Lange syndrome (CdLS) is a multisystem genetic disorder, and cases caused by variants in the structural maintenance of chromosomes protein 3 (SMC3) gene are uncommon. Here, we report two cases of CdLS associated with novel pathogenic variants in SMC3 from two Chinese families.METHODS:
Clinical presentations of two patients with CdLS were evaluated, and specimens from the patients and other family members were collected for Trio-based whole-exome sequencing. Pyrosequencing, chip-based digital PCR, minigene splicing assay, and in silico analysis were carried out to elucidate the impact of novel variants.RESULTS:
Novel heterozygous variants in SMC3 were identified in each proband. One harbored a novel splicing and mosaic variant (c.2535+1G>A) in SMC3. The mutated allele G>A conversion was approximately 23.1% by digital PCR, which indicated that 46.2% of peripheral blood cells had this variant. Additionally, in vitro minigene splicing analysis validated that the c.2535+1G>A variant led to an exon skipping in messenger RNA splicing. The other carried a heterozygous variant (c.435C>A), which was predicted to be pathogenic as well as significantly altered in local electrical potential. The former showed multiple abnormalities and marked clinical severity, and the latter mainly exhibited a speech developmental disorder and slightly facial anomalies.CONCLUSION:
Both patients were clinically diagnosed with Cornelia de Lange syndrome 3 (CdLS3). The newly identified SMC3 gene variants can expand the understanding of CdLS3 and provide reliable evidence for genetic counseling to the affected family.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Cromosómicas no Histona
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Proteínas de Ciclo Celular
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Síndrome de Cornelia de Lange
Límite:
Female
/
Humans
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Male
Idioma:
En
Revista:
Mol Genet Genomic Med
Año:
2024
Tipo del documento:
Article
País de afiliación:
China