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Novel Variant in PLAG1 in a Familial Case with Silver-Russell Syndrome Suspicion. Genes (Basel) 2020; 11:genes11121461. [PMID: 33291420 PMCID: PMC7762056 DOI: 10.3390/genes11121461] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 02/06/2023] Open
Abstract
Silver-Russell syndrome (SRS) is a rare growth-related genetic disorder that is mainly associated with prenatal and postnatal growth retardation. Molecular causes are not clear in all cases, the most common ones being loss of methylation on chromosome 11p15 (≈50%) and maternal uniparental disomy for chromosome 7 (upd(7)mat) (≈10%). However, pathogenic variants in genes such as CDKN1C, HMGA2, IGF2, or PLAG1 have also been described. Previously, two families and one sporadic case have been reported with PLAG1 alterations. Here, we present a case of a female with clinical suspicion of SRS (i.e., intrauterine and postnatal growth retardation, triangular face, psychomotor delay, speech delay, feeding difficulties). No alterations in methylation or copy number were detected at chromosomes 11p15 and 7 using methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA). The custom panel study by next-generation sequencing (NGS) revealed a frameshift variant in the PLAG1 gene (NM_002655.3:c.551delA; p.(Lys184Serfs *45)). Familial studies confirmed that the variant was inherited from the mother and it was also present in other family members. New evidence of pathogenic alterations in the HMGA2-PLAG1-IGF2 pathway suggest the importance of studying and taking into account these genes as alternative molecular causes of Silver-Russell syndrome.
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Abstract
Imprinting disorders are a group of congenital diseases caused by dysregulation of genomic imprinting, affecting prenatal and postnatal growth, neurocognitive development, metabolism and cancer predisposition. Aberrant expression of imprinted genes can be achieved through different mechanisms, classified into epigenetic - if not involving DNA sequence change - or genetic in the case of altered genomic sequence. Despite the underlying mechanism, the phenotype depends on the parental allele affected and opposite phenotypes may result depending on the involvement of the maternal or the paternal chromosome. Imprinting disorders are largely underdiagnosed because of the broad range of clinical signs, the overlap of presentation among different disorders, the presence of mild phenotypes, the mitigation of the phenotype with age and the limited availability of molecular techniques employed for diagnosis. This review briefly illustrates the currently known human imprinting disorders, highlighting endocrinological aspects of pediatric interest.
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Affiliation(s)
- Diana Carli
- University of Torino, Department of Pediatric and Public Health Sciences, Torino, Italy
| | - Evelise Riberi
- University of Torino, Department of Pediatric and Public Health Sciences, Torino, Italy
| | | | - Alessandro Mussa
- University of Torino, Department of Pediatric and Public Health Sciences, Torino, Italy,* Address for Correspondence: University of Torino, Department of Pediatric and Public Health Sciences, Torino, Italy Phone: +39-011-313-1985 E-mail:
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Beygo J, Küchler A, Gillessen-Kaesbach G, Albrecht B, Eckle J, Eggermann T, Gellhaus A, Kanber D, Kordaß U, Lüdecke HJ, Purmann S, Rossier E, van de Nes J, van der Werf IM, Wenzel M, Wieczorek D, Horsthemke B, Buiting K. New insights into the imprinted MEG8-DMR in 14q32 and clinical and molecular description of novel patients with Temple syndrome. Eur J Hum Genet 2017. [PMID: 28635951 DOI: 10.1038/ejhg.2017.91] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The chromosomal region 14q32 contains several imprinted genes, which are expressed either from the paternal (DLK1 and RTL1) or the maternal (MEG3, RTL1as and MEG8) allele only. Imprinted expression of these genes is regulated by two differentially methylated regions (DMRs), the germline DLK1/MEG3 intergenic (IG)-DMR (MEG3/DLK1:IG-DMR) and the somatic MEG3-DMR (MEG3:TSS-DMR), which are methylated on the paternal and unmethylated on the maternal allele. Disruption of imprinting in the 14q32 region results in two clinically distinct imprinting disorders, Temple syndrome (TS14) and Kagami-Ogata syndrome (KOS14). Another DMR with a yet unknown function is located in intron 2 of MEG8 (MEG8-DMR, MEG8:Int2-DMR). In contrast to the IG-DMR and the MEG3-DMR, this somatic DMR is methylated on the maternal chromosome and unmethylated on the paternal chromosome. We have performed extensive methylation analyses by deep bisulfite sequencing of the IG-DMR, MEG3-DMR and MEG8-DMR in different prenatal tissues including amniotic fluid cells and chorionic villi. In addition, we have studied the methylation pattern of the MEG8-DMR in different postnatal tissues. We show that the MEG8-DMR is hypermethylated in each of 13 non-deletion TS14 patients (seven newly identified and six previously published patients), irrespective of the underlying molecular cause, and is always hypomethylated in the four patients with KOS14, who have different deletions not encompassing the MEG8-DMR itself. The size and the extent of the deletions and the resulting methylation pattern suggest that transcription starting from the MEG3 promoter may be necessary to establish the methylation imprint at the MEG8-DMR.
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Affiliation(s)
- Jasmin Beygo
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Alma Küchler
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | | | - Beate Albrecht
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Jonas Eckle
- Sozialpädiatrisches Zentrum, St. Elisabeth-Stiftung, Ravensburg, Germany
| | | | - Alexandra Gellhaus
- Klinik für Frauenheilkunde und Geburtshilfe, Universitätsklinikum Essen, Essen, Germany
| | - Deniz Kanber
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Ulrike Kordaß
- MVZ für Humangenetik und Molekularpathologie Rostock, Zweigstelle Greifswald, Greifswald, Germany
| | - Hermann-Josef Lüdecke
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany.,Institut für Humangenetik, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Sabine Purmann
- Institut für Humangenetik, Universität zu Lübeck, Lübeck, Germany
| | - Eva Rossier
- Institut für Medizinische Genetik und angewandte Genomik, Universiät Tübingen, Tübingen, Germany.,Genetikum Stuttgart, Stuttgart, Germany
| | - Johannes van de Nes
- Institute of Neuropathology, Faculty of Medicine, University Duisburg-Essen, Essen, Germany.,Institute of Pathology, University of Bochum, Bochum, Germany
| | | | | | - Dagmar Wieczorek
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany.,Institut für Humangenetik, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Bernhard Horsthemke
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Karin Buiting
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
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