An overlapping phenotype of Osteogenesis imperfecta and Ehlers-Danlos syndrome due to a heterozygous mutation in COL1A1 and biallelic missense variants in TNXB identified by whole exome sequencing.
Am J Med Genet A
; 170A(4): 1080-5, 2016 Apr.
Article
em En
| MEDLINE
| ID: mdl-26799614
ABSTRACT
Osteogenesis imperfecta (OI) and Ehlers-Danlos syndrome (EDS) are variable genetic disorders that overlap in different ways [Cole 1993; Grahame 1999]. Here, we describe a boy presenting with severe muscular hypotonia, multiple fractures, and joint hyperflexibility, features that are compatible with mild OI and hypermobility type EDS, respectively. By whole exome sequencing, we identified both a COL1A1 mutation (c.4006-1G > A) inherited from the patient's mildly affected mother and biallelic missense variants in TNXB (p.Val1213Ile, p.Gly2592Ser). Analysis of cDNA showed that the COL1A1 splice site mutation led to intron retention causing a frameshift (p.Phe1336Valfs*72). Type 1 collagen secretion by the patient's skin fibroblasts was reduced. Immunostaining of a muscle biopsy obtained from the patient revealed a clear reduction of tenascin-X in the extracellular matrix compared to a healthy control. These findings imply that the combination of the COL1A1 mutation with the TNXB variants might cause the patient's unique phenotype.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Osteogênese Imperfeita
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Fenótipo
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Tenascina
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Colágeno Tipo I
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Síndrome de Ehlers-Danlos
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Heterozigoto
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Mutação
Tipo de estudo:
Prognostic_studies
Limite:
Humans
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Infant
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Male
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article