Deletions in the 3' part of the NFIX gene including a recurrent Alu-mediated deletion of exon 6 and 7 account for previously unexplained cases of Marshall-Smith syndrome.
Hum Mutat
; 35(9): 1092-100, 2014 Sep.
Article
en En
| MEDLINE
| ID: mdl-24924640
ABSTRACT
Marshall-Smith syndrome (MSS) is a very rare malformation syndrome characterized by typical craniofacial anomalies, abnormal osseous maturation, developmental delay, failure to thrive, and respiratory difficulties. Mutations in the nuclear factor 1/X gene (NFIX) were recently identified as the cause of MSS. In our study cohort of 17 patients with a clinical diagnosis of MSS, conventional sequencing of NFIX revealed frameshift and splice-site mutations in 10 individuals. Using multiplex ligation-dependent probe amplification analysis, we identified a recurrent deletion of NFIX exon 6 and 7 in five individuals. We demonstrate this recurrent deletion is the product of a recombination between AluY elements located in intron 5 and 7. Two other patients had smaller deletions affecting exon 6. These findings show that MSS is a genetically homogeneous Mendelian disorder. RT-PCR experiments with newly identified NFIX mutations including the recurrent exon 6 and 7 deletion confirmed previous findings indicating that MSS-associated mutant mRNAs are not cleared by nonsense-mediated mRNA decay. Predicted MSS-associated mutant NFIX proteins consistently have a preserved DNA binding and dimerization domain, whereas they grossly vary in their C-terminal portion. This is in line with the hypothesis that MSS-associated mutations encode dysfunctional proteins that act in a dominant negative manner.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Anomalías Múltiples
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Enfermedades del Desarrollo Óseo
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Exones
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Eliminación de Secuencia
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Anomalías Craneofaciales
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Elementos Alu
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Displasia Septo-Óptica
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Factores de Transcripción NFI
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
Límite:
Adolescent
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Adult
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Child
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Child, preschool
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Female
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Humans
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Infant
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Male
Idioma:
En
Revista:
Hum Mutat
Asunto de la revista:
GENETICA MEDICA
Año:
2014
Tipo del documento:
Article
País de afiliación:
Alemania