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Abstract
The XPG/ERCC5 endonuclease was originally identified as the causative gene for Xeroderma Pigmentosum complementation group G. Ever since its discovery, in depth biochemical, structural and cell biological studies have provided detailed mechanistic insight into its function in excising DNA damage in nucleotide excision repair, together with the ERCC1–XPF endonuclease. In recent years, it has become evident that XPG has additional important roles in genome maintenance that are independent of its function in NER, as XPG has been implicated in protecting replication forks by promoting homologous recombination as well as in resolving R-loops. Here, we provide an overview of the multitasking of XPG in genome maintenance, by describing in detail how its activity in NER is regulated and the evidence that points to important functions outside of NER. Furthermore, we present the various disease phenotypes associated with inherited XPG deficiency and discuss current ideas on how XPG deficiency leads to these different types of disease.
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Sirchia F, Fantasia I, Feresin A, Giorgio E, Faletra F, Mordeglia D, Barbieri M, Guida V, De Luca A, Stampalija T. Prenatal findings of cataract and arthrogryposis: recurrence of cerebro-oculo-facio-skeletal syndrome and review of differential diagnosis. BMC Med Genomics 2021; 14:89. [PMID: 33766032 PMCID: PMC7992958 DOI: 10.1186/s12920-021-00939-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 03/14/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cerebro-oculo-facio-skeletal syndrome (COFS) is a severe and progressive neurologic condition characterized by prenatal onset of arthrogryposis, cataract, microcephaly and growth failure. The aim of this study was to present a case of recurrence of the COFS syndrome and to propose a differential diagnosis flow-chart in case of prenatal findings of arthrogryposis and cataract. CASE PRESENTATION We report a case of recurrence of COFS3 syndrome within the same family, with similar diagnostic features. In the first case the COFS syndrome remained undiagnosed, while in the second case, due to prenatal findings of arthrogryposis and cataract, genetic investigation focusing on responsible genes of COFS (ERCC5, ERCC6 and FKTN genes) was carried out. The fetus was found to be compound heterozygous for two different ERCC5 mutations, confirming the clinical suspect of COFS syndrome. A review of the literature on possible causative genes of prenatal cataract and arthrogryposis was performed and we present a flow-chart to guide differential diagnosis and possible genetic testing in case of these findings. CONCLUSION COFS syndrome is a rare autosomic recessive condition. However, it can be suspected and diagnosed prenatally. The flow-chart illustrates a pathway to guide differential diagnosis according to the prenatal findings. Main syndromes, key testing and specific genes are included. Targeted molecular testing should be offered to the couple in order to reach a diagnosis and assess the recurrence risk for future pregnancies.
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Affiliation(s)
- Fabio Sirchia
- Department of Molecular Medicine, University of Pavia, Via Forlanini 14, 27100, Pavia, Italy.
| | - Ilaria Fantasia
- Unit of Fetal Medicine e Prenatal Diagnosis, Institute for Maternal and Child Health IRCCS "Burlo Garofolo", Trieste, Italy
| | - Agnese Feresin
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | - Elisa Giorgio
- Department of Medical Sciences, University of Torino, Turin, Italy
| | - Flavio Faletra
- Department of Medical Genetics, Institute for Maternal and Child Health IRCCS "Burlo Garofolo", Trieste, Italy
| | - Denise Mordeglia
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | - Moira Barbieri
- Unit of Fetal Medicine e Prenatal Diagnosis, Institute for Maternal and Child Health IRCCS "Burlo Garofolo", Trieste, Italy
| | - Valentina Guida
- Division of Medical Genetics, Fondazione IRCCS-Casa Sollievo della Sofferenza, 71013, San Giovanni Rotondo, Foggia, Italy
| | - Alessandro De Luca
- Division of Medical Genetics, Fondazione IRCCS-Casa Sollievo della Sofferenza, 71013, San Giovanni Rotondo, Foggia, Italy
| | - Tamara Stampalija
- Unit of Fetal Medicine e Prenatal Diagnosis, Institute for Maternal and Child Health IRCCS "Burlo Garofolo", Trieste, Italy.,Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy
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Panigrahi I, Shankar Prasad BA, Kaur H, Kalra J. COFS type 3 in an Indian family with antenatally detected arthrogryposis. Am J Med Genet A 2020; 185:631-635. [PMID: 33219753 DOI: 10.1002/ajmg.a.61979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 10/28/2020] [Accepted: 10/31/2020] [Indexed: 11/09/2022]
Abstract
Fetal akinesia and contractures can be caused by mutations in various genes that lead to overlapping phenotypes with contractures, rocker bottom feet, cerebellar hypoplasia, ventriculomegaly, growth retardation, pulmonary hypoplasia, cystic hygroma and cleft palate in various combinations. Cerebro-oculo-facio-skeletal (COFS) syndrome is a condition resulting from defects in DNA repair pathway, and genes involved include ERCC1 (COFS), ERCC2 (XPD), ERCC5(XPG), and ERCC6 (CSB). It is a severe disorder presenting in fetal or neonatal period with microcephaly, arthrogryposis, prominent nose, and kyphoscoliosis, and leads to early death in childhood. We report a baby with antenatally identified arthrogryposis in which the homozygous pathogenic variant in exon 8 was identified in ERCC5 gene, by targeted next generation sequencing. This was predicted to cause premature chain termination in the protein. ERCC5 gene is mainly implicated in xeroderma pigmentosum, sometimes in COFS syndrome.
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Affiliation(s)
| | | | - Harleen Kaur
- Department of Pediatrics, PGIMER, Chandigarh, India
| | - Jasvinder Kalra
- Department of Obstetrics and Gynecology, PGIMER, Chandigarh, India
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