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Kaur P, do Rosario MC, Hebbar M, Sharma S, Kausthubham N, Nair K, Shrikiran A, Bhat Y R, Lewis LES, Nampoothiri S, Patil SJ, Suresh N, Bijarnia Mahay S, Dua Puri R, Pai S, Kaur A, KC R, Kamath N, Bajaj S, Kumble A, Shetty R, Shenoy R, Kamate M, Shah H, Muranjan MN, BL Y, Avabratha KS, Subramaniam G, Kadavigere R, Bielas S, Girisha KM, Shukla A. Clinical and genetic spectrum of 104 Indian families with central nervous system white matter abnormalities. Clin Genet 2021; 100:542-550. [PMID: 34302356 PMCID: PMC8918360 DOI: 10.1111/cge.14037] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 12/15/2022]
Abstract
Genetic disorders with predominant central nervous system white matter abnormalities (CNS WMAs), also called leukodystrophies, are heterogeneous entities. We ascertained 117 individuals with CNS WMAs from 104 unrelated families. Targeted genetic testing was carried out in 16 families and 13 of them received a diagnosis. Chromosomal microarray (CMA) was performed for three families and one received a diagnosis. Mendeliome sequencing was used for testing 11 families and all received a diagnosis. Whole exome sequencing (WES) was performed in 80 families and was diagnostic in 52 (65%). Singleton WES was diagnostic for 50/75 (66.67%) families. Overall, genetic diagnoses were obtained in 77 families (74.03%). Twenty-two of 47 distinct disorders observed in this cohort have not been reported in Indian individuals previously. Notably, disorders of nuclear mitochondrial pathology were most frequent (9 disorders in 20 families). Thirty-seven of 75 (49.33%) disease-causing variants are novel. To sum up, the present cohort describes the phenotypic and genotypic spectrum of genetic disorders with CNS WMAs in our population. It demonstrates WES, especially singleton WES, as an efficient tool in the diagnosis of these heterogeneous entities. It also highlights possible founder events and recurrent disease-causing variants in our population and their implications on the testing strategy.
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Affiliation(s)
- Parneet Kaur
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Michelle C do Rosario
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Malavika Hebbar
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Suvasini Sharma
- Department of Paediatrics, Lady Hardinge Medical College and Associated Kalawati Saran Children’s Hospital, New Delhi, India
| | - Neethukrishna Kausthubham
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Karthik Nair
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - A Shrikiran
- Department of Paediatrics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Ramesh Bhat Y
- Department of Paediatrics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Leslie Edward S Lewis
- Department of Paediatrics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Sheela Nampoothiri
- Department of Paediatric Genetics, Amrita Institute of Medical Sciences and Research Centre, Kochi, India
| | - SJ Patil
- Division of Genetics, Mazumdar Shaw Medical Centre, Narayana Health City, Bangalore, India
| | - Narayanaswami Suresh
- Department of Paediatrics, Lady Hardinge Medical College and Associated Kalawati Saran Children’s Hospital, New Delhi, India
| | - Sunita Bijarnia Mahay
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - Ratna Dua Puri
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - Shivanand Pai
- Department of Neurology, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, India
| | - Anupriya Kaur
- Department of Paediatrics, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Rakshith KC
- Department of Neurology, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, India
| | - Nutan Kamath
- Department of Paediatrics, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, India
| | - Shruti Bajaj
- Jaslok Hospital and Research Centre, Mumbai, India
| | - Ali Kumble
- Department of Paediatrics, Indiana Hospital and Heart Institute, Mangalore, India
| | | | - Rathika Shenoy
- Department of Paediatrics, K.S. Hegde Medical Academy, NITTE University, Mangalore, India
| | - Mahesh Kamate
- Department of Paediatrics, Jawaharlal Nehru Medical College, Belgaum, India
| | - Hitesh Shah
- Department of Orthopaedics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Mamta N Muranjan
- Department of Pediatrics, Genetics Division, Seth Gordhandas Sunderdas Medical College and King Edward VII Memorial Hospital, Parel, Mumbai, Maharashtra, India
| | - Yatheesha BL
- Dheemahi Child Neurology and Development Center, Shimoga, India
| | | | | | - Rajagopal Kadavigere
- Department of Radiodiagnosis, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Stephanie Bielas
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Katta Mohan Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
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Sharawat IK, Panda PK, Dawman L. Spastic Paraplegia-56 due to a Novel CYP2U1 Truncating Mutation in an Indian Boy: A New Report and Literature Review. J Pediatr Neurosci 2021; 16:71-74. [PMID: 34316314 PMCID: PMC8276956 DOI: 10.4103/jpn.jpn_86_20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/07/2020] [Indexed: 11/22/2022] Open
Abstract
Spastic paraplegia-56 is a rare autosomal recessive disorder, caused by homozygous or compound heterozygous mutations in the CYP2U1 gene, located on chromosome 4. Till date, only 28 patients with this disorder have been reported in the literature. We report a new case of CYP2U1-related spastic paraplegia-56. We also reviewed previously published patients with this condition from various databases. Next-generation sequencing in the index child detected a novel homozygous two base pair deletion in exon 2 of the CYP2U1 gene that results in a frameshift and premature truncation of the protein 19 amino-acid downstream to codon 361. Together with the presented case, 29 were available for analysis. The mean age at the diagnosis was 17.84 ± 6.86 years. Intellectual disability/cognitive dysfunction and delayed walking or gait disturbance were the most common presenting features. Around half of the patients had neuroregression in between 1 and 2 years. It is clinically imperative to suspect this disease in children with early-onset spastic paraparesis, especially in cases accompanied by baseline development delay or cognitive impairment and consanguinity.
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Affiliation(s)
- Indar K Sharawat
- Pediatric Neurology Division, Department of Pediatrics, All India Institute of Medical Sciences (AIIMS), Rishikesh, Uttarakhand, India
| | - Prateek Kumar Panda
- Pediatric Neurology Division, Department of Pediatrics, All India Institute of Medical Sciences (AIIMS), Rishikesh, Uttarakhand, India
| | - Lesa Dawman
- Department of Pediatrics, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
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