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Lau NKC, Lee HHC, Chen SPL, Ng CWY, Mak CM, Chong YK, Tong TTY, Leung MT, Shek CC, Yuen YP, Ching CK. In-house multiplex ligation-dependent probe amplification assay for citrin deficiency: analytical validation and novel exonic deletions in SLC25A13. Pathology 2021; 53:867-874. [PMID: 34045052 DOI: 10.1016/j.pathol.2021.02.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/11/2021] [Accepted: 02/05/2021] [Indexed: 11/26/2022]
Abstract
Citrin deficiency is one of the most common inborn errors of metabolism in East Asians, which may manifest as neonatal cholestasis, failure to thrive and dyslipidaemia, or recurrent hyperammonaemic encephalopathy. Its molecular diagnosis requires confirmation of the presence of biallelic pathogenic variants in SLC25A13 gene by sequencing, and analysis for a common insertion IVS16ins3kb. However, patients with compatible biochemical features but only one monoallelic pathogenic variant have remained a diagnostic challenge. Here we report the development, validation and application of a multiplex ligation-dependent probe amplification (MLPA) assay using an in-house oligonucleotide probemix and a customised Coffalyer.NET worksheet for detection of exonic copy number variations in SLC25A13. With this MLPA assay, we successfully identified the presence of a heterozygous exonic deletion in SLC25A13 in three of 15 (20%) unrelated individuals with only one monoallelic pathogenic variant detected using conventional methods. Three exonic deletions, two novel involving exon 14 and one reported involving exon 5, were subsequently confirmed with Sanger sequencing. In summary, we developed, evaluated, and demonstrated the clinical utility of an in-house MLPA assay to look for exonic deletions in SLC25A13 in patients with citrin deficiency. With the discovery of novel deletions, MLPA should be considered a test of choice for molecular diagnosis of citrin deficiency when the sequencing result is inconclusive.
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Affiliation(s)
- Nike Kwai Cheung Lau
- Kowloon West Cluster Laboratory Genetic Service, Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | - Hencher Han Chih Lee
- Kowloon West Cluster Laboratory Genetic Service, Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | - Sammy Pak Lam Chen
- Kowloon West Cluster Laboratory Genetic Service, Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | - Candy Wai Yan Ng
- Kowloon West Cluster Laboratory Genetic Service, Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | - Chloe Miu Mak
- Kowloon West Cluster Laboratory Genetic Service, Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | - Yeow Kuan Chong
- Kowloon West Cluster Laboratory Genetic Service, Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | - Tammy Tsz Yan Tong
- Kowloon West Cluster Laboratory Genetic Service, Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | - Mei Tik Leung
- Department of Pathology, Queen Elizabeth Hospital, Hong Kong, China
| | - Chi Chung Shek
- Department of Pathology, Queen Elizabeth Hospital, Hong Kong, China
| | - Yuet Ping Yuen
- Department of Chemical Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Chor Kwan Ching
- Kowloon West Cluster Laboratory Genetic Service, Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong, China.
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Abeshi A, Bruson A, Beccari T, Dundar M, D’Esposito F, Bertelli M. Genetic testing for X-linked juvenile retinoschisis. EUROBIOTECH JOURNAL 2017. [DOI: 10.24190/issn2564-615x/2017/s1.35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract
We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for X-linked juvenile retinoschisis (XJR). The disease has X-linked inheritance, a prevalence that varies from one in 5000 to one in 25000 males, and is caused by mutations in the RS1 gene. Clinical diagnosis is based on clinical findings, ophthalmological examination, electroretinography and optical coherence tomography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.
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Affiliation(s)
- Andi Abeshi
- MAGI Balkans, Tirana , Albania
- MAGI’S Lab, Rovereto , Italy
| | | | - Tommaso Beccari
- Department of Pharmaceutical Sciences, University of Perugia, Perugia , Italy
| | - Munis Dundar
- Department of Medical Genetics, Erciyes University Medical School, Kayseri , Turkey
| | - Fabiana D’Esposito
- Head and Neck Department, School of Medicine and Surgery, University of Naples “Federico II”, Napoli , Italy
- ICORG (Imperial College Ophthalmology Research Group), Western Eye Hospital, London , UK
- MAGI Euregio, Bolzano , Italy
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