1
|
Calì F, Vinci M, Treccarichi S, Papa C, Gloria A, Musumeci A, Federico C, Vitello GA, Nicotera AG, Di Rosa G, Vetri L, Saccone S, Elia M. PLEKHG1: New Potential Candidate Gene for Periventricular White Matter Abnormalities. Genes (Basel) 2024; 15:1096. [PMID: 39202455 PMCID: PMC11353482 DOI: 10.3390/genes15081096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Revised: 08/16/2024] [Accepted: 08/19/2024] [Indexed: 09/03/2024] Open
Abstract
Hypoxic-ischemic brain damage presents a significant neurological challenge, often manifesting during the perinatal period. Specifically, periventricular leukomalacia (PVL) is emerging as a notable contributor to cerebral palsy and intellectual disabilities. It compromises cerebral microcirculation, resulting in insufficient oxygen or blood flow to the periventricular region of the brain. As widely documented, these pathological conditions can be caused by several factors encompassing preterm birth (4-5% of the total cases), as well single cotwin abortion and genetic variants such as those associated with GTPase pathways. Whole exome sequencing (WES) analysis identified a de novo causative variant within the pleckstrin homology domain-containing family G member 1 (PLEKHG1) gene in a patient presenting with PVL. The PLEKHG1 gene is ubiquitously expressed, showing high expression patterns in brain tissues. PLEKHG1 is part of a family of Rho guanine nucleotide exchange factors, and the protein is essential for cell division control protein 42 (CDC42) activation in the GTPase pathway. CDC42 is a key small GTPase of the Rho-subfamily, regulating various cellular functions such as cell morphology, migration, endocytosis, and cell cycle progression. The molecular mechanism involving PLEKHG1 and CDC42 has an intriguing role in the reorientation of cells in the vascular endothelium, thus suggesting that disruption responses to mechanical stress in endothelial cells may be involved in the formation of white matter lesions. Significantly, CDC42 association with white matter abnormalities is underscored by its MIM phenotype number. In contrast, although PLEKHG1 has been recently associated with patients showing white matter hyperintensities, it currently lacks a MIM phenotype number. Additionally, in silico analyses classified the identified variant as pathogenic. Although the patient was born prematurely and subsequently to dichorionic gestation, during which its cotwin died, we suggest that the variant described can strongly contribute to PVL. The aim of the current study is to establish a plausible association between the PLEKHG1 gene and PVL.
Collapse
Affiliation(s)
- Francesco Calì
- Oasi Research Institute—IRCCS, 94018 Troina, Italy; (F.C.); (M.V.); (S.T.); (C.P.); (A.G.); (A.M.); (G.A.V.); (L.V.); (M.E.)
| | - Mirella Vinci
- Oasi Research Institute—IRCCS, 94018 Troina, Italy; (F.C.); (M.V.); (S.T.); (C.P.); (A.G.); (A.M.); (G.A.V.); (L.V.); (M.E.)
| | - Simone Treccarichi
- Oasi Research Institute—IRCCS, 94018 Troina, Italy; (F.C.); (M.V.); (S.T.); (C.P.); (A.G.); (A.M.); (G.A.V.); (L.V.); (M.E.)
| | - Carla Papa
- Oasi Research Institute—IRCCS, 94018 Troina, Italy; (F.C.); (M.V.); (S.T.); (C.P.); (A.G.); (A.M.); (G.A.V.); (L.V.); (M.E.)
| | - Angelo Gloria
- Oasi Research Institute—IRCCS, 94018 Troina, Italy; (F.C.); (M.V.); (S.T.); (C.P.); (A.G.); (A.M.); (G.A.V.); (L.V.); (M.E.)
| | - Antonino Musumeci
- Oasi Research Institute—IRCCS, 94018 Troina, Italy; (F.C.); (M.V.); (S.T.); (C.P.); (A.G.); (A.M.); (G.A.V.); (L.V.); (M.E.)
| | - Concetta Federico
- Department Biological, Geological and Environmental Sciences, University of Catania, Via Androne 81, 95124 Catania, Italy;
| | - Girolamo Aurelio Vitello
- Oasi Research Institute—IRCCS, 94018 Troina, Italy; (F.C.); (M.V.); (S.T.); (C.P.); (A.G.); (A.M.); (G.A.V.); (L.V.); (M.E.)
| | - Antonio Gennaro Nicotera
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age, “Gaetano Barresi” University of Messina, 98124 Messina, Italy; (A.G.N.); (G.D.R.)
| | - Gabriella Di Rosa
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age, “Gaetano Barresi” University of Messina, 98124 Messina, Italy; (A.G.N.); (G.D.R.)
| | - Luigi Vetri
- Oasi Research Institute—IRCCS, 94018 Troina, Italy; (F.C.); (M.V.); (S.T.); (C.P.); (A.G.); (A.M.); (G.A.V.); (L.V.); (M.E.)
| | - Salvatore Saccone
- Department Biological, Geological and Environmental Sciences, University of Catania, Via Androne 81, 95124 Catania, Italy;
| | - Maurizio Elia
- Oasi Research Institute—IRCCS, 94018 Troina, Italy; (F.C.); (M.V.); (S.T.); (C.P.); (A.G.); (A.M.); (G.A.V.); (L.V.); (M.E.)
| |
Collapse
|
2
|
Hu YY, Song W, Liu ZG, Ye XG, Zhang HW, Li X, Luo JX, Wang PY, Wang J, Lin XF, Zhu HL, Liao WP, Li B, Chen XQ. ARHGAP4 variants are associated with X-linked early-onset temporal lobe epilepsy. World J Pediatr 2024; 20:859-867. [PMID: 39060771 DOI: 10.1007/s12519-024-00830-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 07/04/2024] [Indexed: 07/28/2024]
Affiliation(s)
- Yuan-Yuan Hu
- Department of Neurology, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Chang-gang-dong Road, Guangzhou, 510260, China
- Epilepsy Center and Neurology Department of Children's Hospital of Soochow University, Suzhou, 215000, Jiangsu, China
| | - Wang Song
- Department of Neurology, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Chang-gang-dong Road, Guangzhou, 510260, China
| | - Zhi-Gang Liu
- Department of pediatrics, Foshan Women and Children Hospital, Foshan, 528000, China
| | - Xing-Guang Ye
- Department of pediatrics, Foshan Women and Children Hospital, Foshan, 528000, China
| | - Hong-Wei Zhang
- Children's Hospital Affiliated to Shandong University, Jinan, 250000, Shandong, China
| | - Xin Li
- Second Hospital of Shandong University, Jinan, 250000, China
| | - Jun-Xia Luo
- Children's Hospital Affiliated to Shandong University, Jinan, 250000, Shandong, China
| | - Peng-Yu Wang
- Department of Neurology, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Chang-gang-dong Road, Guangzhou, 510260, China
| | - Jie Wang
- Department of Neurology, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Chang-gang-dong Road, Guangzhou, 510260, China
| | - Xiao-Fei Lin
- Huai'an Maternity & Child Healthcare Hospital, Huai'an, 223001, China
| | - Hong-Li Zhu
- Huai'an Maternity & Child Healthcare Hospital, Huai'an, 223001, China
| | - Wei-Ping Liao
- Department of Neurology, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Chang-gang-dong Road, Guangzhou, 510260, China
| | - Bin Li
- Institute of Neuroscience of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Chang-gang-dong Road 250, Guangzhou, 510260, Guangdong, China.
| | - Xu-Qin Chen
- Epilepsy Center and Neurology Department of Children's Hospital of Soochow University, Suzhou, 215000, Jiangsu, China.
| |
Collapse
|
3
|
Du W, Verma A, Ye Q, Du W, Lin S, Yamanaka A, Klein OD, Hu JK. Myosin II mediates Shh signals to shape dental epithelia via control of cell adhesion and movement. PLoS Genet 2024; 20:e1011326. [PMID: 38857279 PMCID: PMC11192418 DOI: 10.1371/journal.pgen.1011326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 06/21/2024] [Accepted: 05/29/2024] [Indexed: 06/12/2024] Open
Abstract
The development of ectodermal organs begins with the formation of a stratified epithelial placode that progressively invaginates into the underlying mesenchyme as the organ takes its shape. Signaling by secreted molecules is critical for epithelial morphogenesis, but how that information leads to cell rearrangement and tissue shape changes remains an open question. Using the mouse dentition as a model, we first establish that non-muscle myosin II is essential for dental epithelial invagination and show that it functions by promoting cell-cell adhesion and persistent convergent cell movements in the suprabasal layer. Shh signaling controls these processes by inducing myosin II activation via AKT. Pharmacological induction of AKT and myosin II can also rescue defects caused by the inhibition of Shh. Together, our results support a model in which the Shh signal is transmitted through myosin II to power effective cellular rearrangement for proper dental epithelial invagination.
Collapse
Affiliation(s)
- Wei Du
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
- School of Dentistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Adya Verma
- Department of Orofacial Sciences, University of California San Francisco, San Francisco, California, United States of America
| | - Qianlin Ye
- School of Dentistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Wen Du
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Sandy Lin
- School of Dentistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Atsushi Yamanaka
- Department of Oral Anatomy and Cell Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Ophir D. Klein
- Department of Orofacial Sciences, University of California San Francisco, San Francisco, California, United States of America
- Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Jimmy K. Hu
- School of Dentistry, University of California Los Angeles, Los Angeles, California, United States of America
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, United States of America
| |
Collapse
|
4
|
Saida K, Chong PF, Yamaguchi A, Saito N, Ikehara H, Koshimizu E, Miyata R, Ishiko A, Nakamura K, Ohnishi H, Fujioka K, Sakakibara T, Asada H, Ogawa K, Kudo K, Ohashi E, Kawai M, Abe Y, Tsuchida N, Uchiyama Y, Hamanaka K, Fujita A, Mizuguchi T, Miyatake S, Miyake N, Kato M, Kira R, Matsumoto N. Monogenic causes of pigmentary mosaicism. Hum Genet 2022; 141:1771-1784. [PMID: 35503477 DOI: 10.1007/s00439-022-02437-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 01/28/2022] [Indexed: 12/30/2022]
Abstract
Pigmentary mosaicism of the Ito type, also known as hypomelanosis of Ito, is a neurocutaneous syndrome considered to be predominantly caused by somatic chromosomal mosaicism. However, a few monogenic causes of pigmentary mosaicism have been recently reported. Eleven unrelated individuals with pigmentary mosaicism (mostly hypopigmented skin) were recruited for this study. Skin punch biopsies of the probands and trio-based blood samples (from probands and both biological parents) were collected, and genomic DNA was extracted and analyzed by exome sequencing. In all patients, plausible monogenic causes were detected with somatic and germline variants identified in five and six patients, respectively. Among the somatic variants, four patients had MTOR variant (36%) and another had an RHOA variant. De novo germline variants in USP9X, TFE3, and KCNQ5 were detected in two, one, and one patients, respectively. A maternally inherited PHF6 variant was detected in one patient with hyperpigmented skin. Compound heterozygous GTF3C5 variants were highlighted as strong candidates in the remaining patient. Exome sequencing, using patients' blood and skin samples is highly recommended as the first choice for detecting causative genetic variants of pigmentary mosaicism.
Collapse
Affiliation(s)
- Ken Saida
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Pin Fee Chong
- Department of Pediatric Neurology, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Asuka Yamaguchi
- Department of Pediatrics, Tokyo-Kita Medical Center, Tokyo, Japan
| | - Naka Saito
- Department of Pediatrics, Tsuruoka Municipal Shonai Hospital, Yamagata, Japan
| | - Hajime Ikehara
- Department of Pediatrics, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Eriko Koshimizu
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Rie Miyata
- Department of Pediatrics, Tokyo-Kita Medical Center, Tokyo, Japan
| | - Akira Ishiko
- Department of Dermatology, Toho University School of Medicine, Tokyo, Japan
| | - Kazuyuki Nakamura
- Department of Pediatrics, Faculty of Medicine, Yamagata University, Yamagata, Japan
| | - Hidenori Ohnishi
- Department of Pediatrics, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Kei Fujioka
- Center of General Internal Medicine and Rheumatology, Gifu Municipal Hospital, Gifu, Japan
| | - Takafumi Sakakibara
- Department of Pediatrics, Nara Medical University School of Medicine, Nara, Japan
| | - Hideo Asada
- Department of Dermatology, Nara Medical University School of Medicine, Nara, Japan
| | - Kohei Ogawa
- Department of Dermatology, Nara Medical University School of Medicine, Nara, Japan
| | - Kyoko Kudo
- Department of Dermatology, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Eri Ohashi
- Division of Neurology, National Center for Child Health and Development, Tokyo, Japan
| | - Michiko Kawai
- Division of Neurology, National Center for Child Health and Development, Tokyo, Japan
| | - Yuichi Abe
- Division of Neurology, National Center for Child Health and Development, Tokyo, Japan
| | - Naomi Tsuchida
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.,Department of Rare Disease Genomics, Yokohama City University Hospital, Yokohama, Japan
| | - Yuri Uchiyama
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.,Department of Rare Disease Genomics, Yokohama City University Hospital, Yokohama, Japan
| | - Kohei Hamanaka
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Atsushi Fujita
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Takeshi Mizuguchi
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
| | - Satoko Miyatake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.,Clinical Genetics Department, Yokohama City University Hospital, Yokohama, Japan
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.,Department of Human Genetics, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Mitsuhiro Kato
- Department of Pediatrics, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan
| | - Ryutaro Kira
- Department of Pediatric Neurology, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.
| |
Collapse
|
5
|
Cai ZR, McCuaig C, Hatami A, Rivière JB, Marcoux D. A novel pathogenic RHOA variant in a patient with patterned cutaneous hypopigmentation associated with extracutaneous findings. Pediatr Dermatol 2022; 39:281-287. [PMID: 35178721 PMCID: PMC9305257 DOI: 10.1111/pde.14923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/04/2022] [Accepted: 01/08/2022] [Indexed: 01/12/2023]
Abstract
RHOA-related neuroectodermal syndrome is characterised by linear skin hypopigmentation along Blaschko's lines associated with alopecia, leukoencephalopathy, facial and limb hypoplasia, and ocular, dental, and acral anomalies. Herein, we report a patient with patterned cutaneous hypopigmentation with a similar phenotype due to a novel postzygotic RHOA variant (c.210G>T; p.Arg70Ser). This illustrates that the complexity of the orchestration of morphogenesis and organogenesis can be affected by different variants in the same gene.
Collapse
Affiliation(s)
- Zhuo Ran Cai
- Division of Pediatric Dermatology, Department of Pediatrics, Sainte-Justine University Hospital Centre, University of Montreal, Montreal, Canada
| | - Catherine McCuaig
- Division of Pediatric Dermatology, Department of Pediatrics, Sainte-Justine University Hospital Centre, University of Montreal, Montreal, Canada
| | - Afshin Hatami
- Division of Pediatric Dermatology, Department of Pediatrics, Sainte-Justine University Hospital Centre, University of Montreal, Montreal, Canada
| | - Jean-Baptiste Rivière
- Department of Human Genetics, Faculty of Medicine, McGill University, Montreal, Canada.,Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Danielle Marcoux
- Division of Pediatric Dermatology, Department of Pediatrics, Sainte-Justine University Hospital Centre, University of Montreal, Montreal, Canada
| |
Collapse
|
6
|
Zhang X, Zhang JG, Mu W, Zhou HM, Liu GL, Li Q. The role of daurisoline treatment in hepatocellular carcinoma: Inhibiting vasculogenic mimicry formation and enhancing sensitivity to sorafenib. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2021; 92:153740. [PMID: 34600176 DOI: 10.1016/j.phymed.2021.153740] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 08/27/2021] [Accepted: 09/05/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Vasculogenic mimicry (VM) is a newly described tumor vascular phenomenon that is independent of traditional angiogenesis and provides an adequate blood supply for tumor growth. VM has been consistently observed in different cancer types. Hence, inhibition of VM may be considered a new anticancer therapeutic strategy. PURPOSE This study aimed to elucidate the potential anticancer effect of daurisoline (DS) on hepatocellular carcinoma (HCC) and the potential molecular mechanism by which DS inhibits VM. We also verified whether combination treatment with sorafenib and DS constitutes a novel therapeutic approach to prevent HCC progression. METHODS The effects of DS on proliferation were evaluated by Cell Counting Kit-8 (CCK-8), colony formation, and 5-ethynyl-2'-deoxyuridine (EdU) incorporation assays. 4',6-Diamidino-2-phenylindole (DAPI) staining and flow cytometric analysis were employed to investigate its effects on apoptosis. Western blot analysis, Matrigel tube formation assays, pulldown assays and immunofluorescence staining were applied to validate the potential mechanism by which DS inhibits VM. Mouse xenograft models were used to evaluate anticancer activities. RESULTS DS inhibited HCC cell proliferation, induced HCC cell apoptosis and repressed VM formation by inactivating RhoA/ROCK2-mediated AKT and ERK-p38 MAPK signaling. Additionally, DS dramatically sensitized HCC cell lines to sorafenib, a curative anticancer drug for patients with advanced HCC. CONCLUSIONS Our study provides insights into the molecular mechanisms underlying DS-induced inhibition of VM, which may facilitate the development of a novel clinical anti-HCC drug. Moreover, our findings suggest that the combination of DS and sorafenib constitutes a potential therapeutic strategy for HCC.
Collapse
Affiliation(s)
- Xue Zhang
- Department of Clinical Pharmacy, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 100 Haining Road, Shanghai, 200080, China; Department of Pharmacy, Shanghai Eye Diseases Prevention & Treatment Center, National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai General Hospital, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, 200040, China
| | - Ji-Gang Zhang
- Department of Clinical Pharmacy, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 100 Haining Road, Shanghai, 200080, China
| | - Wan Mu
- Department of Pharmacy, Shanghai Eye Diseases Prevention & Treatment Center, National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai General Hospital, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, 200040, China
| | - He-Ming Zhou
- Department of Clinical Pharmacy, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 100 Haining Road, Shanghai, 200080, China
| | - Gao-Lin Liu
- Department of Clinical Pharmacy, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 100 Haining Road, Shanghai, 200080, China; Department of Pharmacy, Shanghai Eye Diseases Prevention & Treatment Center, National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai General Hospital, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, 200040, China.
| | - Qin Li
- Department of Clinical Pharmacy, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 100 Haining Road, Shanghai, 200080, China.
| |
Collapse
|
7
|
Clinical spectrum of MTOR-related hypomelanosis of Ito with neurodevelopmental abnormalities. Genet Med 2021; 23:1484-1491. [PMID: 33833411 PMCID: PMC8354853 DOI: 10.1038/s41436-021-01161-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 03/16/2021] [Accepted: 03/16/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose Hypomelanosis of Ito (HI) is a skin marker of somatic mosaicism.
Mosaic MTOR pathogenic variants have been
reported in HI with brain overgrowth. We sought to delineate further the
pigmentary skin phenotype and clinical spectrum of neurodevelopmental
manifestations of MTOR-related HI. Methods From two cohorts totaling 71 patients with pigmentary mosaicism, we
identified 14 patients with Blaschko-linear and one with flag-like pigmentation
abnormalities, psychomotor impairment or seizures, and a postzygotic MTOR variant in skin. Patient records, including
brain magnetic resonance image (MRI) were reviewed. Immunostaining (n = 3) for melanocyte markers and
ultrastructural studies (n = 2) were performed on skin biopsies. Results MTOR variants were present in
skin, but absent from blood in half of cases. In a patient (p.[Glu2419Lys]
variant), phosphorylation of p70S6K was constitutively increased. In
hypopigmented skin of two patients, we found a decrease in stage 4 melanosomes
in melanocytes and keratinocytes. Most patients (80%) had macrocephaly or
(hemi)megalencephaly on MRI. Conclusion MTOR-related HI is a recognizable
neurocutaneous phenotype of patterned dyspigmentation, epilepsy, intellectual
deficiency, and brain overgrowth, and a distinct subtype of hypomelanosis
related to somatic mosaicism. Hypopigmentation may be due to a defect in
melanogenesis, through mTORC1 activation, similar to hypochromic patches in
tuberous sclerosis complex. Graphical Abstract ![]()
Collapse
|
8
|
Lam CW, Chan CY, Wong KC, Chang STL. Postzygotic inactivating mutation of KIF13A located at chromosome 6p22.3 in a patient with a novel mosaic neuroectodermal syndrome. J Hum Genet 2021; 66:825-829. [PMID: 33526817 DOI: 10.1038/s10038-020-00883-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 11/02/2020] [Accepted: 11/19/2020] [Indexed: 11/09/2022]
Abstract
Hypomelanosis of Ito (HMI) is part of a neuroectodermal syndrome characterized by distinctive skin manifestations with or without multisystemic involvements. In our undiagnosed diseases program, we have encountered a 3-year-old girl presenting with characteristic skin hypopigmentation suggesting HMI and developmental delay. An exome and genome approach utilizing next-generation sequencing revealed a heterozygous de novo frameshift variant in the KIF13A gene, i.e., NM_022113.6: c.2357dupA, resulting in nonsense-mediated decay. The low mutant allelic ratio suggested that the mutation has occurred postzygotically leading to embryonic mosaicism. Functionally, K1F3A regulates cell membrane blebbing and migration of neural crest cells by controlling recycling of RHOB to the plasma membrane and is also involved in melanosome biogenesis. Importantly, hypopigmentation of the skin has been reported in chr 6p22.3-p23 microdeletion syndrome supporting the association of KIF13A haploinsufficiency with the novel neuroectodermal syndrome. With the increased availability of genome sequencing, we envisage more genetic causes of HMI will be identified in the future.
Collapse
Affiliation(s)
- Ching-Wan Lam
- Department of Pathology, The University of Hong Kong, Hong Kong, China.
| | - Candace Yim Chan
- Department of Pathology, Princess Margaret Hospital, Hong Kong, China.,Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Ka-Chung Wong
- Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | | |
Collapse
|
9
|
Abstract
Understanding the etiology of congenital disorders requires interdisciplinary research and close collaborations between clinicians, geneticists and developmental biologists. The pace of gene discovery has quickened due to advances in sequencing technology, resulting in a wealth of publicly available sequence data but also a gap between gene discovery and crucial mechanistic insights provided by studies in model systems. In this Spotlight, I highlight the opportunities for developmental biologists to engage with human geneticists and genetic resources to advance the study of congenital disorders.
Collapse
|