1
|
Fernandez I, Patey N, Marchand V, Birlea M, Maranda B, Haddad E, Decaluwe H, Le Deist F. Multiple intestinal atresia with combined immune deficiency related to TTC7A defect is a multiorgan pathology: study of a French-Canadian-based cohort. Medicine (Baltimore) 2014; 93:e327. [PMID: 25546680 PMCID: PMC4602622 DOI: 10.1097/md.0000000000000327] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Hereditary multiple intestinal atresia (HMIA) is a rare cause of intestinal obstruction in humans associated with a profound combined immune deficiency. Deleterious mutations of the tetratricopeptide repeat domain-7A (TTC7A) gene lead to HMIA, although the mechanism(s) causing the disease in TTC7A deficiency has (have) not yet been clearly identified. To evaluate the consequences of TTC7A deficiency, we studied the morphology of several organs from HMIA patients at different developmental stages, as well as the expression of the TTC7A protein. We performed histological and immunohistochemical analyses on biopsies and autopsies of 6 patients and 1 fetus with HMIA. Moreover, we characterized for the first time the expression of the TTC7A protein by immunostaining it in several organs from control (including fetal samples), infants, and 1 fetus with HMIA. Besides the gastrointestinal tract, HMIA disease was associated with morphological alterations in multiple organs: thymus, lung, spleen, and liver. Moreover, we demonstrated that normal TTC7A protein was expressed in the cytoplasm of epithelial cells of the intestine, thymus, and pancreas. Surprisingly, altered TTC7A protein was highly expressed in tissues from patients, mainly in the epithelial cells. We have established that HMIA associated with a TTC7A defect is characterized by multiorgan impairments. Overall, this report suggests that TTC7A protein is critical for the proper development, preservation, and/or function of thymic and gastrointestinal epithelium.
Collapse
Affiliation(s)
- Isabel Fernandez
- From the Department of Microbiology, Infectiology and Immunology, University of Montreal, Montreal, Canada (IF, EH, FLD); Department of Microbiology and Immunology, CHU Sainte-Justine, Montreal, Canada (IF, FLD); CHU Sainte-Justine Research Center, Montreal, Canada (IF, NP, EH, HD, FLD); Department of Pathology and Cell Biology, CHU Sainte-Justine and University of Montreal, Montreal, Canada (NP); Department of Paediatrics, University of Montreal, Montreal, Canada (VM, EH, HD, FLD); Division of Gastroenterology, Hepatology and Nutrition, CHU Sainte-Justine, Montreal, Canada (VM); Histology Facility, IRIC, University of Montreal, Montreal, Montreal, Canada (MB); Medical Genetics Service, University of Sherbrooke, Sherbrooke, Canada (BM); and Division of Rheumatology, Immunology and Allergology, CHU Sainte-Justine Montreal, Canada (EH, HD, FLD)
| | | | | | | | | | | | | | | |
Collapse
|
3
|
Samuels ME, Majewski J, Alirezaie N, Fernandez I, Casals F, Patey N, Decaluwe H, Gosselin I, Haddad E, Hodgkinson A, Idaghdour Y, Marchand V, Michaud JL, Rodrigue MA, Desjardins S, Dubois S, Le Deist F, Awadalla P, Raymond V, Maranda B. Exome sequencing identifies mutations in the gene TTC7A in French-Canadian cases with hereditary multiple intestinal atresia. J Med Genet 2013; 50:324-9. [PMID: 23423984 PMCID: PMC3625823 DOI: 10.1136/jmedgenet-2012-101483] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 01/22/2013] [Indexed: 12/23/2022]
Abstract
BACKGROUND Congenital multiple intestinal atresia (MIA) is a severe, fatal neonatal disorder, involving the occurrence of obstructions in the small and large intestines ultimately leading to organ failure. Surgical interventions are palliative but do not provide long-term survival. Severe immunodeficiency may be associated with the phenotype. A genetic basis for MIA is likely. We had previously ascertained a cohort of patients of French-Canadian origin, most of whom were deceased as infants or in utero. The goal of the study was to identify the molecular basis for the disease in the patients of this cohort. METHODS We performed whole exome sequencing on samples from five patients of four families. Validation of mutations and familial segregation was performed using standard Sanger sequencing in these and three additional families with deceased cases. Exon skipping was assessed by reverse transcription-PCR and Sanger sequencing. RESULTS Five patients from four different families were each homozygous for a four base intronic deletion in the gene TTC7A, immediately adjacent to a consensus GT splice donor site. The deletion was demonstrated to have deleterious effects on splicing causing the skipping of the attendant upstream coding exon, thereby leading to a predicted severe protein truncation. Parents were heterozygous carriers of the deletion in these families and in two additional families segregating affected cases. In a seventh family, an affected case was compound heterozygous for the same 4bp deletion and a second missense mutation p.L823P, also predicted as pathogenic. No other sequenced genes possessed deleterious variants explanatory for all patients in the cohort. Neither mutation was seen in a large set of control chromosomes. CONCLUSIONS Based on our genetic results, TTC7A is the likely causal gene for MIA.
Collapse
Affiliation(s)
- Mark E Samuels
- Centre de Recherche du CHU Ste-Justine, University of Montreal, Montreal, Quebec, Canada
| | - Jacek Majewski
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Najmeh Alirezaie
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Isabel Fernandez
- Centre de Recherche du CHU Ste-Justine, University of Montreal, Montreal, Quebec, Canada
- Department of Microbiology and Immunology, University of Montreal, Montreal, Quebec, Canada
| | - Ferran Casals
- Centre de Recherche du CHU Ste-Justine, University of Montreal, Montreal, Quebec, Canada
| | - Natalie Patey
- Centre de Recherche du CHU Ste-Justine, University of Montreal, Montreal, Quebec, Canada
- Department of Pathology, University of Montreal, Montreal, Quebec, Canada
| | - Hélène Decaluwe
- Centre de Recherche du CHU Ste-Justine, University of Montreal, Montreal, Quebec, Canada
- Department of Pediatrics, University of Montreal, Montreal, Quebec, Canada
| | - Isabelle Gosselin
- Department of Neurosciences, Centre de recherche du CHU de Québec, Université Laval, Québec City, Quebec, Canada
| | - Elie Haddad
- Centre de Recherche du CHU Ste-Justine, University of Montreal, Montreal, Quebec, Canada
- Department of Microbiology and Immunology, University of Montreal, Montreal, Quebec, Canada
- Department of Pediatrics, University of Montreal, Montreal, Quebec, Canada
| | - Alan Hodgkinson
- Centre de Recherche du CHU Ste-Justine, University of Montreal, Montreal, Quebec, Canada
| | - Youssef Idaghdour
- Centre de Recherche du CHU Ste-Justine, University of Montreal, Montreal, Quebec, Canada
| | - Valerie Marchand
- Centre de Recherche du CHU Ste-Justine, University of Montreal, Montreal, Quebec, Canada
- Department of Pediatrics, University of Montreal, Montreal, Quebec, Canada
| | - Jacques L Michaud
- Centre de Recherche du CHU Ste-Justine, University of Montreal, Montreal, Quebec, Canada
- Department of Pediatrics, University of Montreal, Montreal, Quebec, Canada
| | - Marc-André Rodrigue
- Department of Neurosciences, Centre de recherche du CHU de Québec, Université Laval, Québec City, Quebec, Canada
- Département de Médecine Moléculaire, Université Laval, Québec City, Quebec, Canada
| | - Sylvie Desjardins
- Department of Neurosciences, Centre de recherche du CHU de Québec, Université Laval, Québec City, Quebec, Canada
| | - Stéphane Dubois
- Department of Neurosciences, Centre de recherche du CHU de Québec, Université Laval, Québec City, Quebec, Canada
| | - Francoise Le Deist
- Centre de Recherche du CHU Ste-Justine, University of Montreal, Montreal, Quebec, Canada
- Department of Microbiology and Immunology, University of Montreal, Montreal, Quebec, Canada
| | - Philip Awadalla
- Centre de Recherche du CHU Ste-Justine, University of Montreal, Montreal, Quebec, Canada
- Department of Pediatrics, University of Montreal, Montreal, Quebec, Canada
| | - Vincent Raymond
- Department of Neurosciences, Centre de recherche du CHU de Québec, Université Laval, Québec City, Quebec, Canada
- Département de Médecine Moléculaire, Université Laval, Québec City, Quebec, Canada
| | - Bruno Maranda
- Medical Genetics Service, University of Sherbrooke, Sherbrooke, Quebec, Canada
| |
Collapse
|