1
|
Lee M, Lui ACY, Chan JCK, Doong PHL, Kwong AKY, Mak CCY, Li RHW, Kan ASY, Chung BHY. Revealing parental mosaicism: the hidden answer to the recurrence of apparent de novo variants. Hum Genomics 2023; 17:91. [PMID: 37798624 PMCID: PMC10557286 DOI: 10.1186/s40246-023-00535-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 09/18/2023] [Indexed: 10/07/2023] Open
Abstract
Mosaicism refers to the presence of two or more populations of genetically distinct cells within an individual, all of which originate from a single zygote. Previous literature estimated the percentage of parental mosaicism ranged from 0.33 to 25.9%. In this study, parents whose children had previously been diagnosed with developmental disorders with an apparent de novo variant were recruited. Peripheral blood, buccal and semen samples were collected from these parents if available for the detection of potential parental mosaicism using droplet digital PCR, complemented with the method of blocker displacement amplification. Among the 20 families being analyzed, we report four families with parental mosaicism (4/20, 20%). Two families have maternal gonosomal mosaicism (EYA1 and EBF3) and one family has paternal gonadal mosaicism (CHD7) with a pathogenic/ likely pathogenic variant. One family has a paternal gonosomal mosaicism with a variant of uncertain significance (FLNC) with high clinical relevance. The detectable variant allele frequency in our cohort ranged from 8.7-35.9%, limit of detection 0.08-0.16% based on our in-house EBF3 assay. Detecting parental mosaicism not only informs family with a more accurate recurrence risk, but also facilitates medical teams to create appropriate plans for pregnancy and delivery, offering the most suitable care.
Collapse
Affiliation(s)
- Mianne Lee
- Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Room 115, 1/F, New Clinical Building, Pok Fu Lam, Hong Kong SAR, China
| | - Adrian C Y Lui
- Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Room 115, 1/F, New Clinical Building, Pok Fu Lam, Hong Kong SAR, China
| | - Joshua C K Chan
- Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Room 115, 1/F, New Clinical Building, Pok Fu Lam, Hong Kong SAR, China
| | - Phoenix H L Doong
- Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Room 115, 1/F, New Clinical Building, Pok Fu Lam, Hong Kong SAR, China
| | - Anna K Y Kwong
- Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Room 115, 1/F, New Clinical Building, Pok Fu Lam, Hong Kong SAR, China
| | - Christopher C Y Mak
- Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Room 115, 1/F, New Clinical Building, Pok Fu Lam, Hong Kong SAR, China
| | - Raymond H W Li
- Department of Obstetrics and Gynaecology, Queen Mary Hospital, Pok Fu Lam, Hong Kong SAR, China
- Department of Obstetrics and Gynaecology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
| | - Anita S Y Kan
- Department of Obstetrics and Gynaecology, Queen Mary Hospital, Pok Fu Lam, Hong Kong SAR, China
- Department of Obstetrics and Gynaecology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
- Prenatal Diagnostic Laboratory, Department of Obstetrics and Gynaecology, Tsan Yuk Hospital, Sai Wan Ho, Hong Kong SAR, China
| | - Brian H Y Chung
- Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Room 115, 1/F, New Clinical Building, Pok Fu Lam, Hong Kong SAR, China.
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Ngau Tau Kok, Hong Kong SAR, China.
| |
Collapse
|
2
|
van Renterghem V, Vilain C, Devriendt K, Casteels I, Smits G, Soblet J, Balikova I. Two siblings with Bosch-Boonstra-Schaaf optic atrophy syndrome due to parental gonadal mosaicism. Eur J Med Genet 2023; 66:104729. [PMID: 36775012 DOI: 10.1016/j.ejmg.2023.104729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 10/01/2022] [Accepted: 02/10/2023] [Indexed: 02/12/2023]
Abstract
Bosch-Boonstra-Schaaf Optic Atrophy Syndrome (BBSOAS, OMIM 615722) is a rare autosomal dominant disorder characterized by intellectual disability, optic atrophy, cortical visual impairment, mild facial dysmorphism, hypotonia, hearing problems, attention deficit and a thin corpus callosum. The gene underlying this disorder is NR2F1 located on chromosome 5q15 which encodes for a nuclear receptor protein. Mutations and deletions have been identified in patients. Here we report on a brother and a sister carrying a pathogenic nonsense NR2F1 variant. The patients have a mild phenotype showing optic atrophy, mild intellectual disability, dysmorphic features and thin corpus callosum. This correlates with previously described milder phenotypes in patients with mutations in this domain. The variant was not identified in the parental genome indicating most likely a gonadal mosaicism. Gonadal mosaicism has not yet been reported in Bosch-Boonstra-Schaaf Optic Atrophy Syndrome.
Collapse
Affiliation(s)
| | - Catheline Vilain
- Department of Genetics, University Hospital Erasme, Brussels, Belgium
| | | | - Ingele Casteels
- Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium
| | - Guillaume Smits
- Department of Genetics, University Hospital Erasme, Brussels, Belgium
| | - Julie Soblet
- Department of Genetics, University Hospital Erasme, Brussels, Belgium
| | - Irina Balikova
- Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium.
| |
Collapse
|
3
|
Guo L, Zhang M, Gao Y, Qin L, Xia H, Liu L, Wang H. A gonadal mosaicism novel KMT2D mutation identified by haplotype construction and clone sequencing strategy. Clin Chim Acta 2022; 531:197-203. [PMID: 35421397 DOI: 10.1016/j.cca.2022.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/08/2022] [Accepted: 04/08/2022] [Indexed: 11/03/2022]
Abstract
Here we reported a pedigree that gave birth to two characteristic clinical signs of Kabuki syndrome daughters. They had an intellectual disability with special facial features. Their eyebrows were relatively wide and the rear 1/3 of the eyebrows was light and sparse. Their eyes were long, narrow, valgus and strabismus. Their noses were broad at the root and flat at the tip. They also had skeletal dysplasia, mainly manifested in the short second knuckle of the little fingers of both hands. Genetic studies showed a novel de novo KMT2D variant (c.16343G>C; p.R5448P) as a cause of Kabuki syndrome. It was very unlikely that the same de novo mutation occurred in two members of a family. Gonadal mosaicism in one of the parents was suspected. Haplotype construction and clone sequencing was used for mutation source analysis. Finally, we inferred that the haplotype from the mother (Gdel-G-C-T-A) contained the pathogenic mutation. A gonadal mosaicism novel KMT2D mutation was identified in their mother.
Collapse
Affiliation(s)
- Liangjie Guo
- Medical Genetics Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou 450003, China
| | - Mengting Zhang
- Medical Genetics Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou 450003, China
| | - Yue Gao
- Medical Genetics Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou 450003, China
| | - Litao Qin
- Medical Genetics Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou 450003, China
| | - Hailan Xia
- National Health Commission Key Laboratory of Birth Defects Prevention, Henan Key Laboratory of Population Defects Prevention, Zhengzhou 450002, China
| | - Lin Liu
- Department of Ultrasound, Fuwai Central China Cardiovascular Hospital, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou 450003, China.
| | - Hongdan Wang
- Medical Genetics Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou 450003, China; National Health Commission Key Laboratory of Birth Defects Prevention, Henan Key Laboratory of Population Defects Prevention, Zhengzhou 450002, China; Henan Provincial People's Hospital, School of Medicine, Henan University, Zhengzhou 450003, China.
| |
Collapse
|
4
|
Kovaleva NV, Cotter PD. Factors affecting clinical manifestation of chromosomal imbalance in carriers of segmental autosomal mosaicism: differential impact of gender. J Appl Genet 2022; 63:281-291. [PMID: 34973130 PMCID: PMC8979927 DOI: 10.1007/s13353-021-00673-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 11/03/2021] [Accepted: 11/25/2021] [Indexed: 11/25/2022]
Abstract
Mosaicism for unbalanced chromosomal rearrangements segmental mosaicism (SM) is rare, both in patients referred for cytogenetic testing and in prenatal diagnoses. In contrast, in preimplantation embryos SM is a frequent finding and, therefore, is even more challenging. However, there is no consistency among results of published studies on the clinical outcomes of embryos with SM, primarily due to the small number of reported cases. Moreover, there is the problem of predicting the potential for the optimal development of a mosaic embryo to a healthy individual. Therefore, we suggested comparing factors predisposing to favorable and poor prognoses, identified in postnatal and prenatal cohorts of SM carriers, with those obtained from studies on preimplantation embryos. We analyzed 580 published cases of SM including (i) postnatally diagnosed affected carriers, (ii) clinically asymptomatic carriers, (iii) prenatally diagnosed carriers, and (iv) miscarriages. We observed a concordance with preimplantation diagnoses regarding the clinical significance of the extent of mosaicism as well as a predominance of deletions over other types of rearrangements. However, there is no concordance regarding excessive involvement of chromosomes 1, 5, and 9 in unbalanced rearrangements and a preferential involvement of larger chromosomes compared to short ones. Paternal age was not found to be associated with SM in postnatally disease-defined individuals. We have identified maternal age and preferential involvement of chromosome 18 in rearrangements associated with clinical manifestations. Male predominance was found among normal pregnancy outcomes and among disease-defined carriers of rearrangements resulting in a gain of genomic material. Female predominance was found among abnormal pregnancy outcomes, among disease-defined carriers of loss and gain/loss rearrangements, and among transmitting carriers of gonadal SM, both affected and asymptomatic. According to data obtained from “post-embryo” studies, clinical manifestations of chromosomal imbalance are associated with a high proportion of abnormal cells, female gender, the type of rearrangement and involved chromosome(s), and maternal age. We believe these data are instructive in the challenging medical genetic counseling of parents faced with no option other than transfer of an embryo with segmental mosaicism.
Collapse
Affiliation(s)
- Natalia V Kovaleva
- Academy of Molecular Medicine, Mytninskaya str., 12/44, St. Petersburg, 191144, Russian Federation.
| | | |
Collapse
|
5
|
Chen CP, Chen CY, Chern SR, Chen SW, Wu FT, Chen WL, Lee MS, Wang W. Prenatal diagnosis of recurrent mosaic ring chromosome 13 of maternal origin. Taiwan J Obstet Gynecol 2021; 60:771-774. [PMID: 34247823 DOI: 10.1016/j.tjog.2021.05.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2021] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE We present prenatal diagnosis of recurrent mosaic ring chromosome 13 [r(13)] of maternal origin. CASE REPORT A 27-year-old woman underwent amniocentesis at 17 weeks of gestation because of a past history of fetal abnormality caused by mosaic r(13) in the previous fetus associated with fetal intrauterine growth restriction (IUGR), a karyotype of 46,XY,r(13)[23]/45,XY,-13[10]/46,XY,idic r(13)[2] and a maternal origin of abnormal r(13). The parental karyotypes were normal. During this pregnancy, amniocentesis revealed a karyotype of 46,XX,r(13)[12]/45,XX,-13[8] and a 22.80-Mb deletion of chromosome 13q31.3-q34. The pregnancy was subsequently terminated, and a malformed fetus was delivered with craniofacial dysmorphism. Repeat amniocentesis revealed a karyotype of 46,XX,r(13)(p11.1q31)[18]/45,XX,-13[12]. The placenta had a karyotype of 46,XX,r(13)(p11.1q31)[27]/45,XY,-13[13]. Polymorphic DNA marker analysis using the DNA derived from the parental bloods and umbilical cord confirmed a maternal origin of the abnormal r(13). CONCLUSION Prenatal diagnosis of mosaic r(13) in consecutive pregnancies should raise a suspicion of parental gonadal mosaicism, and polymorphic DNA marker analysis is useful for determination of the parental origin of recurrent aneuploidy under such a circumstance.
Collapse
Affiliation(s)
- Chih-Ping Chen
- Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan; Department of Biotechnology, Asia University, Taichung, Taiwan; School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan; Institute of Clinical and Community Health Nursing, National Yang Ming Chiao Tung University, Taipei, Taiwan; Department of Obstetrics and Gynecology, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
| | - Chen-Yu Chen
- Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medicine, MacKay Medical College, New Taipei City, Taiwan; MacKay Junior College of Medicine, Nursing and Management, Taipei, Taiwan
| | - Schu-Rern Chern
- Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
| | - Shin-Wen Chen
- Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan
| | - Fang-Tzu Wu
- Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan
| | - Wen-Lin Chen
- Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan
| | - Meng-Shan Lee
- Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan
| | - Wayseen Wang
- Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
| |
Collapse
|
6
|
Koh K, Takaki R, Ishiura H, Tsuji S, Takiyama Y. SPG9A with the new occurrence of an ALDH18A1 mutation in a CMT1A family with PMP22 duplication: case report. BMC Neurol 2021; 21:64. [PMID: 33573605 PMCID: PMC7876803 DOI: 10.1186/s12883-021-02087-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 02/02/2021] [Indexed: 12/03/2022] Open
Abstract
Background ALDH18A1 mutations lead to delta-1-pyrroline-5-carboxylate-synthetase (P5CS) deficiency, which is a urea cycle-related disorder including SPG9A, SPG9B, autosomal dominant cutis laxa-3 (ADCL3), and autosomal recessive cutis laxa type 3A (ARCL3A). These diseases exhibit a broad clinical spectrum, which makes the diagnosis of P5CS deficiency difficult. We report here a rare Japanese family including both patients with an ALDH18A1 mutation (SPG9A) and ones with CMT1A. Case presentation A Japanese family included five patients with the CMT phenotype and five with the HSP phenotype in four generations. The patients with the HSP phenotype showed a pure or complicated form, and intrafamilial clinical variability was noted. Genetically, FISH analysis revealed that two CMT patients had a PMP22 duplication (CMT1A). Exome analysis and Sanger sequencing revealed five HSP patients had an ALDH18A1 heterozygous mutation of c.755G > A, which led to SPG9A. Haplotype analysis revealed that the ALDH18A1 mutation must have newly occurred. To date, although de novo mutations of ALDH18A1 have been described in ADCL3A, they were not mentioned in SPG9A in earlier reports. Thus, this is the first SPG9A family with a de novo mutation or the new occurrence of gonadal mosaicism of ALDH18A1. Analysis of serum amino acid levels revealed that two SPG9A patients and two unaffected family members had low citrulline levels and one had a low level of ornithine. Conclusions Since the newly occurring ALDH18A1 mutation, c.755G > A, is the same as that in two ADHSP families and one sporadic patient with SPG9A reported previously, this genomic site might easily undergo mutation. The patients with the c.755G > A mutation in our family showed clinical variability of symptoms like in the earlier reported two families and one sporadic patient with this mutation. Further studies are required to clarify the relationship between the amino acid levels and clinical manifestations, which will reveal how P5CS deficiency influences disease phenotypes including ARCL3A, ADCL3, SPG9B, and SPG9A.
Collapse
Affiliation(s)
- Kishin Koh
- Department of Neurology, Graduate School of Medical Sciences, University of Yamanashi, Yamanashi, 409-3898, Japan
| | - Ryusuke Takaki
- Department of Neurology, Graduate School of Medical Sciences, University of Yamanashi, Yamanashi, 409-3898, Japan.,Department of Neurology, Iida Hospital, Nagano, 395-8505, Japan
| | - Hiroyuki Ishiura
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
| | - Shoji Tsuji
- Department of Molecular Neurology, University of Tokyo, Graduate School of Medicine, Tokyo, 113-8655, Japan.,Department of Neurology, International University of Health and Welfare, Chiba, 286-8686, Japan
| | - Yoshihisa Takiyama
- Department of Neurology, Graduate School of Medical Sciences, University of Yamanashi, Yamanashi, 409-3898, Japan.
| |
Collapse
|
7
|
Alkaya DU, Karaman B, Tüysüz B. Three Offspring with Cri-du-Chat Syndrome from Phenotypically Normal Parents. Mol Syndromol 2020; 11:97-103. [PMID: 32655341 DOI: 10.1159/000506892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2020] [Indexed: 12/14/2022] Open
Abstract
Cri-du-chat syndrome is characterized by facial dysmorphism, intellectual disability, and multiple congenital anomalies. Most cases occur de novo. Here, we report 3 siblings with cri-du-chat syndrome born to healthy parents. The proband was admitted to our clinic at the age of 6.5 years due to severe intellectual disability, facial dysmorphism, and heart defect. His karyotype showed a deletion of chromosome 5p. Microarray analysis revealed a 29-Mb deletion in chromosome 5p and a 4.7-Mb duplication in chromosome 19q. FISH analysis indicated an unbalanced translocation between 5p13.3 and 19q13.4. During follow-up, the second and the third child of the family were born with the same chromosome abnormality. Parental peripheral blood and skin fibroblast karyotypes as well as the FISH results using chromosome 5p- and 19q-specific subtelomeric probes were normal. FISH analysis of the father's sperm detected a 5p deletion in 12.8% of 200 cells, and microarray analysis confirmed the same unbalanced chromosome abnormality in a mosaic pattern. Uncultured peripheral blood and buccal smear of the father were also studied by FISH to exclude low-level mosaicism and in vitro culture effect. This is the first study that provides molecular evidence of paternal gonadal mosaicism of an unbalanced translocation detected in 3 siblings with cri-du-chat syndrome.
Collapse
Affiliation(s)
- Dilek U Alkaya
- Department of Pediatric Genetics, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey
| | - Birsen Karaman
- Department of Medical Genetics, Medical School, Istanbul University, Istanbul, Turkey
| | - Beyhan Tüysüz
- Department of Pediatric Genetics, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey
| |
Collapse
|
8
|
Zahn CA, Itin P. Papular Epidermal Nevus with "Skyline" Basal Cell Layer Syndrome - Natural Course: Case Report and Literature Review. Case Rep Dermatol 2017; 9:1-5. [PMID: 28203156 PMCID: PMC5301115 DOI: 10.1159/000454757] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 11/27/2016] [Indexed: 11/19/2022] Open
Abstract
Papular epidermal nevus with “skyline” basal cell layer (PENS) is a very rare type of keratinocytic nevus and is associated with extracutaneous findings such as neurological symptoms in about 50% of the cases. Therefore, it is also referred to as PENS syndrome. Clinically visible hyperkeratotic papules and plaques already appear at birth or shortly thereafter, while neurological symptoms such as epilepsy and mental retardation manifest themselves during childhood. Genetics suggests gonadal mosaicism as a possible cause for the disease. Another hypothesis is that genetic mutation can occur in a mendelian trait or through a paradominant inheritance.
Collapse
Affiliation(s)
| | - Peter Itin
- Department of Dermatology, University Hospital Basel, Basel, Switzerland; Department of Biomedicine, University Hospital Basel, Basel, Switzerland
| |
Collapse
|
9
|
Gigante L, Paganini I, Frontali M, Ciabattoni S, Sangiuolo FC, Papi L. Rhabdoid tumor predisposition syndrome caused by SMARCB1 constitutional deletion: prenatal detection of new case of recurrence in siblings due to gonadal mosaicism. Fam Cancer 2016; 15:123-6. [PMID: 26342593 DOI: 10.1007/s10689-015-9836-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Rhabdoid tumors are aggressive malignancies that show loss-of-function mutations of SMARCB1 gene, a member of the SWI/SNF chromatin-remodeling complex controlling gene transcription. One-third of patients affected by rhabdoid tumor harbor a germ-line mutation of SMARCB1 defining a rhabdoid tumor predisposition syndrome. The occurrence of a second somatic mutation determines the development of neoplasia in a two-hit model. Most germ-line mutations occur de novo, and few cases of recurrence in a sibship have been described. Here we report on a new Italian family with recurrence of SMARCB1 germ-line deletion in two siblings due to gonadal mosaicism. The deletion was identified in the 9-month-old proband with malignant rhabdoid tumor of the right kidney and disseminated metastases. Testing of both parents confirmed the de novo origin of the mutation, but recurrence was then detected prenatally in a new pregnancy. This is the sixth family with malignant rhabdoid tumor predisposition syndrome with the recurrence of the same germ-line SMARCB1 mutation in the sibship but not in healthy parents, suggesting that gonadal mosaicism is a less rare event than supposed. The clinical outcome in our patient confirms previous data of poorer outcome in patients with rhabdoid tumor predisposition syndrome.
Collapse
|
10
|
Danda S, van Rahden VA, John D, Paul P, Raju R, Koshy S, Kutsche K. Evidence of Germline Mosaicism for a Novel BCOR Mutation in Two Indian Sisters with Oculo-Facio-Cardio-Dental Syndrome. Mol Syndromol 2014; 5:251-6. [PMID: 25337074 DOI: 10.1159/000365768] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/30/2013] [Indexed: 02/04/2023] Open
Abstract
In this study, we report on 2 sisters from India with oculo-facio-cardio-dental (OFCD) syndrome caused by a novel heterozygous mutation c.3490C>T (p.R1164*) in the BCOR gene. OFCD syndrome is an X-linked inherited disorder which is lethal in males. Interestingly, both parents of the sisters were phenotypically normal, and DNA analysis from blood and buccal or saliva cells failed to detect the BCOR mutation found in their 2 daughters. To the best of our knowledge, for the first time, we provide indirect evidence of germline mosaicism for the BCOR mutation in one of the parents of the 2 sisters affected by OFCD syndrome. Although this condition is lethal in males, gonadal mosaicism could also be present in the father. The relevance of clinical diagnosis and mutation analysis required for genetic counseling is described in this family.
Collapse
Affiliation(s)
- Sumita Danda
- Department of Clinical Genetics, Christian Medical College and Hospital, Vellore, India
| | - Vanessa A van Rahden
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Deepa John
- Department of Ophthalmology, Christian Medical College and Hospital, Vellore, India
| | - Padma Paul
- Department of Ophthalmology, Christian Medical College and Hospital, Vellore, India
| | - Renu Raju
- Department of Ophthalmology, Christian Medical College and Hospital, Vellore, India
| | - Santosh Koshy
- Department of Dental Surgery, Christian Medical College and Hospital, Vellore, India
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|