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Frontiers in Aging 2023Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive disorder characterized by a range of clinical symptoms, including poikiloderma, juvenile cataracts, short... (Review)
Review
Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive disorder characterized by a range of clinical symptoms, including poikiloderma, juvenile cataracts, short stature, sparse hair, eyebrows/eyelashes, nail dysplasia, and skeletal abnormalities. While classically associated with mutations in the gene, which encodes a DNA helicase involved in DNA replication and repair, three additional genes have been recently identified in RTS: , encoding a subunit of the APC/C complex; which encodes a nuclease/helicase involved in DNA repair; and , encoding a poorly characterized protein implicated in excitatory synapse formation and splicing. Here, we review the clinical spectrum of RTS patients, analyze the genetic basis of the disease, and discuss molecular functions of the affected genes, drawing some novel genotype-phenotype correlations and proposing avenues for future studies into this enigmatic disorder.
PubMed: 38021400
DOI: 10.3389/fragi.2023.1296409 -
Genetics in Medicine : Official Journal... Jul 2023Rothmund-Thomson syndrome (RTS) is characterized by poikiloderma, sparse hair, small stature, skeletal defects, cancer, and cataracts, resembling features of premature...
PURPOSE
Rothmund-Thomson syndrome (RTS) is characterized by poikiloderma, sparse hair, small stature, skeletal defects, cancer, and cataracts, resembling features of premature aging. RECQL4 and ANAPC1 are the 2 known disease genes associated with RTS in >70% of cases. We describe RTS-like features in 5 individuals with biallelic variants in CRIPT (OMIM 615789).
METHODS
Two newly identified and 4 published individuals with CRIPT variants were systematically compared with those with RTS using clinical data, computational analysis of photographs, histologic analysis of skin, and cellular studies on fibroblasts.
RESULTS
All CRIPT individuals fulfilled the diagnostic criteria for RTS and additionally had neurodevelopmental delay and seizures. Using computational gestalt analysis, CRIPT individuals showed greatest facial similarity with individuals with RTS. Skin biopsies revealed a high expression of senescence markers (p53/p16/p21) and the senescence-associated ß-galactosidase activity was elevated in CRIPT-deficient fibroblasts. RECQL4- and CRIPT-deficient fibroblasts showed an unremarkable mitotic progression and unremarkable number of mitotic errors and no or only mild sensitivity to genotoxic stress by ionizing radiation, mitomycin C, hydroxyurea, etoposide, and potassium bromate.
CONCLUSION
CRIPT causes an RTS-like syndrome associated with neurodevelopmental delay and epilepsy. At the cellular level, RECQL4- and CRIPT-deficient cells display increased senescence, suggesting shared molecular mechanisms leading to the clinical phenotypes.
Topics: Humans; Rothmund-Thomson Syndrome; Cellular Senescence; DNA Damage; Hydroxyurea; Fibroblasts; Mutation; Adaptor Proteins, Signal Transducing
PubMed: 37013901
DOI: 10.1016/j.gim.2023.100836 -
Journal of Medical Genetics Nov 2023Rothmund-Thomson syndrome (RTS) is a rare, heterogeneous autosomal recessive genodermatosis, with poikiloderma as its hallmark. It is classified into two types: type I,...
Rothmund-Thomson syndrome (RTS) is a rare, heterogeneous autosomal recessive genodermatosis, with poikiloderma as its hallmark. It is classified into two types: type I, with biallelic variants in and juvenile cataracts, and type II, with biallelic variants in , increased cancer risk and no cataracts. We report on six Brazilian probands and two siblings of Swiss/Portuguese ancestry presenting with severe short stature, widespread poikiloderma and congenital ocular anomalies. Genomic and functional analysis revealed compound heterozygosis for a deep intronic splicing variant in trans with loss of function variants in , with reduction of the protein levels and impaired DNA double-strand break repair. The intronic variant is shared by all patients, as well as the Portuguese father of the European siblings, indicating a probable founder effect. Biallelic variants in were previously associated with microcephalic osteodysplastic primordial dwarfism. Although the individuals reported here present a similar growth pattern, the presence of poikiloderma and ocular anomalies is unique. Thus, we have broadened the phenotypical spectrum of mutations, incorporating clinical characteristics of RTS. Although a clear genotype-phenotype correlation cannot be definitively established at this moment, we speculate that the residual activity of the splicing variant allele could be responsible for the distinct manifestations of -related syndromes.
PubMed: 37055165
DOI: 10.1136/jmg-2022-109119 -
The Journal of Biological Chemistry Sep 2023The levels of non-coding RNAs (ncRNAs) are regulated by transcription, RNA processing, and RNA degradation pathways. One mechanism for the degradation of ncRNAs involves... (Review)
Review
The levels of non-coding RNAs (ncRNAs) are regulated by transcription, RNA processing, and RNA degradation pathways. One mechanism for the degradation of ncRNAs involves the addition of oligo(A) tails by non-canonical poly(A) polymerases, which then recruit processive sequence-independent 3' to 5' exonucleases for RNA degradation. This pathway of decay is also regulated by three 3' to 5' exoribonucleases, USB1, PARN, and TOE1, which remove oligo(A) tails and thereby can protect ncRNAs from decay in a manner analogous to the deubiquitination of proteins. Loss-of-function mutations in these genes lead to premature degradation of some ncRNAs and lead to specific human diseases such as Poikiloderma with Neutropenia (PN) for USB1, Dyskeratosis Congenita (DC) for PARN and Pontocerebellar Hypoplasia type 7 (PCH7) for TOE1. Herein, we review the biochemical properties of USB1, PARN, and TOE1, how they modulate ncRNA levels, and their roles in human diseases.
Topics: Humans; Dyskeratosis Congenita; Exoribonucleases; Neutropenia; RNA Stability; RNA, Untranslated; Loss of Function Mutation
PubMed: 37544646
DOI: 10.1016/j.jbc.2023.105139 -
JAAD Case Reports Jun 2024
PubMed: 38741660
DOI: 10.1016/j.jdcr.2023.08.045 -
Cureus Apr 2024Kindler syndrome (KS) is a rare autosomal recessive skin condition. The FERMT1 gene mutates and causes symptoms such as blistering and epidermal atrophy, as well as an...
Kindler syndrome (KS) is a rare autosomal recessive skin condition. The FERMT1 gene mutates and causes symptoms such as blistering and epidermal atrophy, as well as an increased risk of cancer and poor wound healing. A male in his 20s sought treatment for his hyper-hypopigmentation over the body with poikiloderma of the face with thin wrinkled cigarette paper skin in association with photosensitivity. He gave a history of developing blisters all over the body during his childhood, which formed raw areas and eventually healed forming atrophic scars. The objective is to assess the correlation of clinical findings with dermoscopy in a case of KS. KS is a rare disorder with poikiloderma, photosensitivity, and acral bullae in infancy as predominant features. Dermoscopy proves to be a useful tool in the diagnosis of this rare disorder as it helps in the identification of poikiloderma, adermatoglyphia, and cigarette paper scarring.
PubMed: 38765347
DOI: 10.7759/cureus.58433 -
British Journal of Haematology Feb 2024The clinical problem of a non-healing fistula in ano in a child affected with poikiloderma with neutropenia (PN) was the stimulus for an innovative study by Parajuli...
The clinical problem of a non-healing fistula in ano in a child affected with poikiloderma with neutropenia (PN) was the stimulus for an innovative study by Parajuli et al. that sheds light on the pathological mechanisms in this disease. Multiparametric analyses of the patient's blood mononuclear cells by cell culture, flow cytometry and multiplex cytokine assay suggested a block of monocyte differentiation. Monocyte transcriptome profiling revealed a signature consistent with the haematological picture and the clinical presentation. Commentary on: Parajuli et al. Defective monocyte plasticity and altered cAMP pathway characterize USB1-mutated poikiloderma with neutropenia Clericuzio type. Br J Haematol 2024;204:683-693.
Topics: Child; Humans; Skin Abnormalities; Neutropenia; Monocytes; Mutation; Phosphoric Diester Hydrolases
PubMed: 37932156
DOI: 10.1111/bjh.19184 -
Cureus Dec 2023Juvenile dermatomyositis (JDM) is a chronic autoimmune inflammatory disorder and is considered the most common form of idiopathic inflammatory myopathies. JDM primarily...
Juvenile dermatomyositis (JDM) is a chronic autoimmune inflammatory disorder and is considered the most common form of idiopathic inflammatory myopathies. JDM primarily affects the skin and the skeletal muscles. Characteristic signs and symptoms include Gottron papules, heliotrope rash, calcinosis cutis, and symmetrical proximal muscle weakness. However, JDM presenting with generalized scaly poikeloderma is an unfamiliar presentation. Herein we report a 14-month-old female toddler presented with generalized progressive asymptomatic scaly mottled violaceous patches (poikilodermatous) that started when she was seven months old. Her lab results were unremarkable. She was diagnosed with poikilodermatous skin rash with a differential diagnosis of Amyopathic dermatomyositis, poikilodermatous genodermatosis, and patch-stage mycosis fungoides. She was prescribed moisturizer creams only. A year later, during a follow-up, she presented with a full picture of JDM, with a history of scaly poikilodermatous skin patches that became more widespread, frequent choking during oral intake, and not being able to stand and sit unsupported. Laboratory workup was significant for low WBC and hemoglobin counts, along with elevated CPK, LDH, ferritin, CRP, and ESR levels. MRI revealed the right anterior thigh and vastus lateralis subcutaneous edema. Therefore, the child was diagnosed and treated as a case of JDM.
PubMed: 38222200
DOI: 10.7759/cureus.50573