Deletion of REXO1L1 locus in a patient with malabsorption syndrome, growth retardation, and dysmorphic features: a novel recognizable microdeletion syndrome?

作者：D'Apice Maria Rosaria^*; Novelli Antonio; di Masi Alessandra; Biancolella Michela; Antoccia Antonio; Gullotta Francesca; Licata Norma; Minella Daniela; Testa Barbara; Nardone Anna Maria; Palmieri Giampiero; Calabrese Emma; Biancone Livia; Tanzarella Caterina; Frontali Marina; Sangiuolo Federica; Novelli Giuseppe; Pallone Francesco

来源：BMC Medical Genetics, 2015, 16(1): 20.

DOI：10.1186/s12881-015-0164-3

• 8q21.2 microdeletion
• REXO1L1 gene
• aCGH
• CNV
• Facial dysmorphisms
• Inflammation and apoptosis of gastrointestinal mucosa

Background: Copy number variations (CNVs) can contribute to genetic variation among individuals and/or have a significant influence in causing diseases. Many studies consider new CNVs' effects on protein family evolution giving rise to gene duplicates or losses. "Unsuccessful" duplicates that remain in the genome as pseudogenes often exhibit functional roles. So, changes in gene and pseudogene number may contribute to development or act as susceptibility alleles of diseases.
Case presentation: We report a de novo heterozygous 271 Kb microdeletion at 8q21.2 region which includes the family of REXO1L genes and pseudogenes in a young man affected by global development delay, progeroid signs, and gastrointestinal anomalies. Molecular and cellular analysis showed that the REXO1L1 gene hemizygosity in a patient's fibroblasts induces genetic instability and increased apoptosis after treatment with different DNA damage-induced agents.
Conclusions: The present results support the hypothesis that low copy gene number within REXO1L1 cluster could play a significant role in this complex clinical and cellular phenotype.

• 出版日期2015-4-2