Mutations in SPINT2 cause a syndromic form of congenital sodium diarrhea.
Am J Hum Genet
; 84(2): 188-96, 2009 Feb.
Article
em En
| MEDLINE
| ID: mdl-19185281
ABSTRACT
Autosomal-recessive congenital sodium diarrhea (CSD) is characterized by perinatal onset of a persistent watery diarrhea with nonproportionally high fecal sodium excretion. Defective jejunal brush-border Na(+)/H(+) exchange has been reported in three sporadic patients, but the molecular basis of the disease has not been elucidated. We reviewed data from a large cohort of CSD patients (n = 24) and distinguished CSD associated with choanal or anal atresia, hypertelorism, and corneal erosions--i.e., a syndromic form of CSD--occurring in ten families from an isolated form--i.e., classic CSD--presenting in seven families. Patients from both groups have a high risk of mortality due to immediate electrolyte imbalances and complications from long-term parenteral nutrition in the first years of life, but survivors can eventually adapt to partial or complete enteral nutrition. A genome-wide SNP scan was applied and identified a homozygous c.593-1G-->A splicing mutation in SPINT2, encoding a Kunitz-type serine-protease inhibitor, in one extended kindred with syndromic CSD. The same mutation and four distinct, homozygous or compound heterozygous mutations (p.Y163C, c.1A-->T, c.337+2T-->C, c.553+2T-->A) were identified in all syndromic patients. No SPINT2 mutations were found in classic-CSD patients. SPINT2 mutations were associated with loss of protein synthesis or failure to inhibit the serine protease trypsin in vitro. We delineate syndromic CSD as a distinct disease entity caused by SPINT2 loss-of-function mutations. SPINT2 mutations might lead to an excess of yet unknown serine protease activity in affected tissues.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sódio
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Glicoproteínas de Membrana
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Diarreia
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Síndromes de Malabsorção
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Mutação
Tipo de estudo:
Etiology_studies
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Incidence_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Female
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Humans
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Infant
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Male
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Newborn
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article