1. Compound Heterozygosity of Low-Frequency Promoter Deletions and Rare Loss-of-Function Mutations in TXNL4A Causes Burn-McKeown Syndrome.
- Author
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Wieczorek, Dagmar, Newman, William G., Wieland, Thomas, Berulava, Tea, Kaffe, Maria, Falkenstein, Daniela, Beetz, Christian, Graf, Elisabeth, Schwarzmayr, Thomas, Douzgou, Sofia, Clayton-Smith, Jill, Daly, Sarah B., Williams, Simon G., Bhaskar, Sanjeev S., Urquhart, Jill E., Anderson, Beverley, O’Sullivan, James, Boute, Odile, Gundlach, Jasmin, and Czeschik, Johanna Christina
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HETEROZYGOSITY , *PROMOTERS (Genetics) , *DELETION mutation , *GENETIC mutation , *ETIOLOGY of diseases - Abstract
Mutations in components of the major spliceosome have been described in disorders with craniofacial anomalies, e.g., Nager syndrome and mandibulofacial dysostosis type Guion-Almeida. The U5 spliceosomal complex of eight highly conserved proteins is critical for pre-mRNA splicing. We identified biallelic mutations in TXNL4A , a member of this complex, in individuals with Burn-McKeown syndrome (BMKS). This rare condition is characterized by bilateral choanal atresia, hearing loss, cleft lip and/or palate, and other craniofacial dysmorphisms. Mutations were found in 9 of 11 affected families. In 8 families, affected individuals carried a rare loss-of-function mutation (nonsense, frameshift, or microdeletion) on one allele and a low-frequency 34 bp deletion (allele frequency 0.76%) in the core promoter region on the other allele. In a single highly consanguineous family, formerly diagnosed as oculo-oto-facial dysplasia, the four affected individuals were homozygous for a 34 bp promoter deletion, which differed from the promoter deletion in the other families. Reporter gene and in vivo assays showed that the promoter deletions led to reduced expression of TXNL4A . Depletion of TXNL4A ( Dib1 ) in yeast demonstrated reduced assembly of the tri-snRNP complex. Our results indicate that BMKS is an autosomal-recessive condition, which is frequently caused by compound heterozygosity of low-frequency promoter deletions in combination with very rare loss-of-function mutations. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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