Molecular diagnosis of cystic fibrosis by RNA obtained from nasal epithelial cells.
J Cyst Fibros
; 23(4): 788-795, 2024 Jul.
Article
em En
| MEDLINE
| ID: mdl-38151412
ABSTRACT
BACKGROUND:
The diagnosis of cystic fibrosis (CF) is established when characteristic clinical signs are coupled with biallelic CFTR pathogenic variants. No previously reported non-canonical splice site variants have to be considered as variants of uncertain significance unless their effect on splicing has been validated.METHODS:
Two variants identified by next-generation sequencing were evaluated. We assayed their effects on splicing employing RNA analysis and real-time expression quantification from RNA obtained from the nasal epithelial cells of a patient with clinically suspected CF and of two patients with milder phenotypes (CFTR-related disorders).RESULTS:
The variant c.164+2dup causes skipping of exon 2 (p.(Ser18_Glu54del)) and exon 2 plus 3 (p.(Ser18Argfs*16)) in CFTR mRNA. Exon 2 expression in the patient heterozygous for c.164+2dup was decreased to 7 % of the exon 2 expression in the controls. The synonymous variant c.1584G>A causes a partial skipping of exon 11. The exon 11 expression in the two patients heterozygous for this variant was 22 % and 42 % of that of the controls, respectively.CONCLUSION:
We conclude that variant c.164+2dup affects mRNA processing and can be considered a CF-causing variant. The results of the functional assay also showed that the p.(Glu528=) variant, usually categorized as a neutral variant based on epidemiological data, partially affects mRNA processing in our patients. This finding would allow us to reclassify the variant as a CFTR-related variant with incomplete penetrance. RNA obtained from nasal epithelial cells is an easy and accurate tool for CFTR functional studies in patients with unclassified splice variants.Palavras-chave
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Base de dados:
MEDLINE
Assunto principal:
Regulador de Condutância Transmembrana em Fibrose Cística
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Fibrose Cística
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Mucosa Nasal
Limite:
Female
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Humans
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Male
Idioma:
En
Revista:
J Cyst Fibros
Ano de publicação:
2024
Tipo de documento:
Article