Prenatal identification of a pathogenic maternal FGFR1 variant in two consecutive pregnancies with fetal forebrain malformations.

OBJECTIVE: Holoprosencephaly (HPE) is the most common aberration of forebrain development, and it leads to a wide spectrum of developmental and craniofacial anomalies. HPE etiology is highly heterogeneous and includes both chromosomal abnormalities and single-gene defects. METHODS: Here, we report an FGFR1 heterozygous variant detected by prenatal exome sequencing and inherited from the asymptomatic mother, in association with recurrent neurological abnormalities in the HPE spectrum in two consecutive pregnancies. RESULTS: Individuals with germline pathogenic variants in FGFR1 (MIM: 136350) show extensive phenotypic variability, which ranges from asymptomatic carriers to hypogonadotropic hypogonadism, arhinencephaly, Kallmann's syndrome with associated features such as cleft lip and palate, skeletal anomalies, isolated HPE, and Hartsfield syndrome. CONCLUSION: The presented case supports the role of exome sequencing in prenatal diagnosis when fetal midline structural anomalies are suggestive of a genetic etiology, as early as the first trimester of gestation. The profound heterogeneity of FGFR1 allelic disorders needs to be considered when planning prenatal screening even in asymptomatic carriers.

Clinical and functional characterization of COL2A1 p.Gly444Ser variant: From a fetal phenotype to a previously undisclosed postnatal phenotype.

COL2A1 gene encodes the alpha-1 chain of type-II procollagen. Heterozygous pathogenic variants are associated with the broad clinical spectrum of genetic diseases known as type-II collagenopathies. We aimed to characterize the NM_001844.5:c.1330G>A;p.Gly444Ser variant detected in the COL2A1 gene through trio-based prenatal exome sequencing in a fetus presenting a severe skeletal phenotype at 31 Gestational Weeks and in his previously undisclosed mild-affected father. Functional studies on father's cutaneous fibroblasts, along with in silico protein modeling and in vitro chondrocytes differentiation, showed intracellular accumulation of collagen-II, its localization in external Golgi vesicles and nuclear morphological alterations. Extracellular matrix showed a disorganized fibronectin network. These results showed that p.Gly444Ser variant alters procollagen molecules processing and the assembly of mature type-II collagen fibrils, according to COL2A1-chain disorganization, displayed by protein modeling. Clinical assessment at 38 y.o., through a reverse-phenotyping approach, revealed limp gait, short and stocky appearance. X-Ray and MRI showed pelvis asymmetry with severe morpho-structural alterations of the femoral heads bilaterally, consistent with a mild form of type-II collagenopathy. This study shows how the fusion of genomics and clinical expertise can drive a diagnosis supported by cellular and bioinformatics studies to effectively establish variants pathogenicity.

In Cis Effect of DMPK Expanded Alleles in Myotonic Dystrophy Type 1 Patients Carrying Variant Repeats at 5' and 3' Ends of the CTG Array.

Myotonic dystrophy type 1 (DM1) is an autosomal dominant multisystemic disease caused by a CTG repeat expansion in the 3'-untranslated region (UTR) of DMPK gene. DM1 alleles containing non-CTG variant repeats (VRs) have been described, with uncertain molecular and clinical consequences. The expanded trinucleotide array is flanked by two CpG islands, and the presence of VRs could confer an additional level of epigenetic variability. This study aims to investigate the association between VR-containing DMPK alleles, parental inheritance and methylation pattern of the DM1 locus. The DM1 mutation has been characterized in 20 patients using a combination of SR-PCR, TP-PCR, modified TP-PCR and LR-PCR. Non-CTG motifs have been confirmed by Sanger sequencing. The methylation pattern of the DM1 locus was determined by bisulfite pyrosequencing. We characterized 7 patients with VRs within the CTG tract at 5' end and 13 patients carrying non-CTG sequences at 3' end of the DM1 expansion. DMPK alleles with VRs at 5' end or 3' end were invariably unmethylated upstream of the CTG expansion. Interestingly, DM1 patients with VRs at the 3' end showed higher methylation levels in the downstream island of the CTG repeat tract, preferentially when the disease allele was maternally inherited. Our results suggest a potential correlation between VRs, parental origin of the mutation and methylation pattern of the DMPK expanded alleles. A differential CpG methylation status could play a role in the phenotypic variability of DM1 patients, representing a potentially useful diagnostic tool.

From cue to meaning: The involvement of POLD1 gene in DNA replication, repair and aging.

Aging is an extremely complex biological process. Aging, cancer and inflammation represent a trinity, object of many interesting researches. The accumulation of DNA damage and its consequences progressively interfere with cellular function and increase susceptibility to developing aging condition. DNA Polymerase delta (Pol δ), encoded by POLD1 gene (MIM#174761) on 19q13.3, is well implicated in many steps of the replication program and repair. Thanks to its exonuclease and polymerase activities, the enzyme is involved in the regulation of the cell cycle, DNA synthesis, and DNA damage repair processes. Damaging variants within the exonuclease domain predispose to cancers, while those occurring in the polymerase active site cause the autosomal dominant Progeroid Syndrome called MDPL, Mandibular hypoplasia, Deafness and Progeroid features with concomitant Lipodystrophy Since DNA damage represents the main cause of ageing and age-related pathologies, an overview of critical Pol δ activities will allow to better understand the associations between DNA damage and nearly every aspect of the ageing process, helping the researchers to counteract all the ageing-pathologies at the same time.

Characterization of full-length CNBP expanded alleles in myotonic dystrophy type 2 patients by Cas9-mediated enrichment and nanopore sequencing.

Myotonic dystrophy type 2 (DM2) is caused by CCTG repeat expansions in the CNBP gene, comprising 75 to >11,000 units and featuring extensive mosaicism, making it challenging to sequence fully expanded alleles. To overcome these limitations, we used PCR-free Cas9-mediated nanopore sequencing to characterize CNBP repeat expansions at the single-nucleotide level in nine DM2 patients. The length of normal and expanded alleles can be assessed precisely using this strategy, agreeing with traditional methods, and revealing the degree of mosaicism. We also sequenced an entire ~50 kbp expansion, which has not been achieved previously for DM2 or any other repeat-expansion disorders. Our approach precisely counted the repeats and identified the repeat pattern for both short interrupted and uninterrupted alleles. Interestingly, in the expanded alleles, only two DM2 samples featured the expected pure CCTG repeat pattern, while the other seven presented also TCTG blocks at the 3' end, which have not been reported before in DM2 patients, but confirmed hereby with orthogonal methods. The demonstrated approach simultaneously determines repeat length, structure/motif, and the extent of somatic mosaicism, promising to improve the molecular diagnosis of DM2 and achieve more accurate genotype-phenotype correlations for the better stratification of DM2 patients in clinical trials.

Mitochondrial dysfunction in mandibular hypoplasia, deafness and progeroid features with concomitant lipodystrophy (MDPL) patients.

Mandibular hypoplasia, Deafness and Progeroid features with concomitant Lipodystrophy is a rare, genetic, premature aging disease named MDPL Syndrome, due to almost always a de novo variant in POLD1 gene, encoding the DNA polymerase δ. In previous in vitro studies, we have already described several hallmarks of aging, including genetic damage, telomere shortening, cell senescence and proliferation defects. Since a clear connection has been reported between telomere shortening and mitochondria malfunction to initiate the aging process, we explored the role that mitochondrial metabolism and activity play in pathogenesis of MDPL Syndrome, an aspect that has not been addressed yet. We thus evaluated mtDNA copy number, assessing a significant decrease in mutated cells. The expression level of genes related to mitochondrial biogenesis and activity also revealed a significant reduction, highlighting a mitochondrial dysfunction in MDPL cells. Even the expression levels of mitochondrial marker SOD2, as assessed by immunofluorescence, were reduced. The decrease in this antioxidant enzyme correlated with increased production of mitochondrial ROS in MDPL cells, compared to WT. Consistent with these data, Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM) analysis revealed in MDPL cells fewer mitochondria, which also displayed morphological abnormalities. Accordingly, we detected autophagic vacuoles containing partially digested mitochondria. Overall, our results demonstrate a dramatic impairment of mitochondrial biogenesis and activity in MDPL Syndrome. Administration of Metformin, though unable to restore mitochondrial impairment, proved efficient in rescuing nuclear abnormalities, suggesting its use to specifically ameliorate the premature aging phenotype.

Characterization of FMR1 Repeat Expansion and Intragenic Variants by Indirect Sequence Capture.

Traditional methods for the analysis of repeat expansions, which underlie genetic disorders, such as fragile X syndrome (FXS), lack single-nucleotide resolution in repeat analysis and the ability to characterize causative variants outside the repeat array. These drawbacks can be overcome by long-read and short-read sequencing, respectively. However, the routine application of next-generation sequencing in the clinic requires target enrichment, and none of the available methods allows parallel analysis of long-DNA fragments using both sequencing technologies. In this study, we investigated the use of indirect sequence capture (Xdrop technology) coupled to Nanopore and Illumina sequencing to characterize FMR1, the gene responsible of FXS. We achieved the efficient enrichment (> 200×) of large target DNA fragments (~60-80 kbp) encompassing the entire FMR1 gene. The analysis of Xdrop-enriched samples by Nanopore long-read sequencing allowed the complete characterization of repeat lengths in samples with normal, pre-mutation, and full mutation status (> 1 kbp), and correctly identified repeat interruptions relevant for disease prognosis and transmission. Single-nucleotide variants (SNVs) and small insertions/deletions (indels) could be detected in the same samples by Illumina short-read sequencing, completing the mutational testing through the identification of pathogenic variants within the FMR1 gene, when no typical CGG repeat expansion is detected. The study successfully demonstrated the parallel analysis of repeat expansions and SNVs/indels in the FMR1 gene at single-nucleotide resolution by combining Xdrop enrichment with two next-generation sequencing approaches. With the appropriate optimization necessary for the clinical settings, the system could facilitate both the study of genotype-phenotype correlation in FXS and enable a more efficient diagnosis and genetic counseling for patients and their relatives.

A 14-Year Italian Experience in DM2 Genetic Testing: Frequency and Distribution of Normal and Premutated CNBP Alleles.

Myotonic dystrophy type 2 (DM2) is a multisystemic disorder caused by a (CCTG) n in intron 1 of the CNBP gene. The CCTG repeat tract is part of a complex (TG) v (TCTG) w (CCTG) x (NCTG) y (CCTG) z motif generally interrupted in CNBP healthy range alleles. Here we report our 14-year experience of DM2 postnatal genetic testing in a total of 570 individuals. The DM2 locus has been analyzed by a combination of SR-PCR, TP-PCR, LR-PCR, and Sanger sequencing of CNBP alleles. DM2 molecular diagnosis has been confirmed in 187/570 samples analyzed (32.8%) and is mainly associated with the presence of myotonia in patients. This set of CNBP alleles showed unimodal distribution with 25 different alleles ranging from 108 to 168 bp, in accordance with previous studies on European populations. The most frequent CNBP alleles consisted of 138, 134, 140, and 136 bps with an overall locus heterozygosity of 90%. Sequencing of 103 unexpanded CNBP alleles in DM2-positive patients revealed that (CCTG)5(NCTG)3(CCTG)7 and (CCTG)6(NCTG)3(CCTG)7 are the most common interruption motifs. We also characterized five CNBP premutated alleles with (CCTG) n repetitions from n = 36 to n = 53. However, the molecular and clinical consequences in our cohort of samples are not unequivocal. Data that emerged from this study are representative of the Italian population and are useful tools for National and European centers offering DM2 genetic testing and counseling.

Functional analysis of POLD1 p.ser605del variant: the aging phenotype of MDPL syndrome is associated with an impaired DNA repair capacity.

Mandibular hypoplasia, Deafness and Progeroid features with concomitant Lipodystrophy define a rare systemic disorder, named MDPL Syndrome, due to almost always a de novo variant in POLD1 gene, encoding the DNA polymerase δ. We report a MDPL female heterozygote for the recurrent p.Ser605del variant. In order to deepen the functional role of the in frame deletion affecting the polymerase catalytic site of the protein, cellular phenotype has been characterised. MDPL fibroblasts exhibit in vitro nuclear envelope anomalies, accumulation of prelamin A and presence of micronuclei. A decline of cell growth, cellular senescence and a blockage of proliferation in G0/G1 phase complete the aged cellular picture. The evaluation of the genomic instability reveals a delayed recovery from DNA induced-damage. Moreover, the rate of telomere shortening was greater in pathological cells, suggesting the telomere dysfunction as an emerging key feature in MDPL. Our results suggest an alteration in DNA replication/repair function of POLD1 as a primary pathogenetic cause of MDPL. The understanding of the mechanisms linking these cellular characteristics to the accelerated aging and to the wide spectrum of affected tissues and clinical symptoms in the MDPL patients may provide opportunities to develop therapeutic treatments for progeroid syndromes.

Interleukin-6 neutralization ameliorates symptoms in prematurely aged mice.

Hutchinson-Gilford progeria syndrome (HGPS) causes premature aging in children, with adipose tissue, skin and bone deterioration, and cardiovascular impairment. In HGPS cells and mouse models, high levels of interleukin-6, an inflammatory cytokine linked to aging processes, have been detected. Here, we show that inhibition of interleukin-6 activity by tocilizumab, a neutralizing antibody raised against interleukin-6 receptors, counteracts progeroid features in both HGPS fibroblasts and LmnaG609G/G609G progeroid mice. Tocilizumab treatment limits the accumulation of progerin, the toxic protein produced in HGPS cells, rescues nuclear envelope and chromatin abnormalities, and attenuates the hyperactivated DNA damage response. In vivo administration of tocilizumab reduces aortic lesions and adipose tissue dystrophy, delays the onset of lipodystrophy and kyphosis, avoids motor impairment, and preserves a good quality of life in progeroid mice. This work identifies tocilizumab as a valuable tool in HGPS therapy and, speculatively, in the treatment of a variety of aging-related disorders.

Genetics and Genomics of Breast Cancer: update and translational perspectives.

In the recent years the rapid scientific innovation in the evaluation of the individual's genome have allowed the identification of variants associated with the onset, treatment and prognosis of various pathologies including cancer, and with a potential impact in the assessment of therapy responses. Despite the analysis and interpretation of genomic information is considered incomplete, in many cases the identification of specific genomic profile has allowed the stratification of subgroups of patients characterized by a better response to drug therapies. Individual genome analysis has changed profoundly the diagnostic and therapeutic approach of breast cancer in the last 15 years by identifying selective molecular lesions that drive the development of neoplasms, showing that each tumor has its own genomic signature, with some specific features and some features common to several sub-types. Several personalized therapies have been (and still are being) developed showing a remarkable efficacy in the treatment of breast cancer.

Expression profiles of the SARS-CoV-2 host invasion genes in nasopharyngeal and oropharyngeal swabs of COVID-19 patients.

We collect the nasopharyngeal and oropharyngeal swabs of 63 subjects with severe symptoms or contacts with COVID-19 confirmed cases to perform a pilot-study aimed to verify the "in situ" expression of SARS-CoV-2 host invasion genes (ACE2, TMPRSS2, PCSK3, EMILIN1, EMILIN2, MMRN1, MMRN2, DPP4). ACE2 (FC = +1.88, p ≤ 0.05) and DPP4 (FC = +3, p < 0.01) genes showed a significant overexpression in COVID-19 patients. ACE2 and DPP4 expression levels had a good performance (AUC = 0.75; p < 0.001) in distinguishing COVID-19 patients from negative subjects. Interestingly, we found a significant positive association of ACE2 mRNA and PCSK3, EMILIN1, MMRN1 and MMRN2 expression and of DPP4 mRNA and EMILIN2 expression only in COVID-19 patients. Noteworthy, a subgroup of severe COVID-19 (n = 7) patients, showed significant high level of ACE2 mRNA and another subgroup of less severe COVID-19 patients (n = 6) significant raised DPP4 levels. These results indicate that a group of SARS-CoV-2 host invasion genes are functionally related in COVID-19 patients and suggests that ACE2 and DPP4 expression level could act as genomic biomarkers. Moreover, at the best of our knowledge, this is the first study that shows an elevated DPP4 expression in naso- and oropharyngeal swabs of COVID-19 patient thus suggesting a functional role of DPP4 in SARS-CoV-2 infections.

Analysis of ACE2 genetic variants in 131 Italian SARS-CoV-2-positive patients.

BACKGROUND: Coronaviruses (CoV) are a large family of viruses that are common in humans and many animal species. Animal coronaviruses rarely infect humans with the exceptions of the Middle East respiratory syndrome ( MERS-CoV ), the severe acute respiratory syndrome corona virus (SARS-CoV), and now SARS-CoV-2, which is the cause of the ongoing pandemic of coronavirus disease 2019 (COVID-19). Several studies suggested that genetic variants in the ACE2 gene may influence the host susceptibility or resistance to SARS-CoV-2 infection according to the functional role of ACE2 in human pathophysiology. However, many of these studies have been conducted in silico based on epidemiological and population data. We therefore investigated the occurrence of ACE2 variants in a cohort of 131 Italian unrelated individuals clinically diagnosed with COVID-19 and in an Italian control population, to evaluate a possible allelic association with COVID-19, by direct DNA analysis. METHODS: As a pilot study, we analyzed, by whole-exome sequencing, genetic variants of ACE2 gene in 131 DNA samples of COVID-19 patients hospitalized at Tor Vergata University Hospital and at Bambino Gesù Children's Hospital, Rome. We used a large control group consisting of 1000 individuals (500 males and 500 females). RESULTS: We identified three different germline variants: one intronic c.439+4G>A and two missense c.1888G>C p.(Asp630His) and c.2158A>G p.(Asn720Asp) in a total of 131 patients with a similar frequency in male and female. Thus far, only the c.1888G>C p.(Asp630His) variant shows a statistically different frequency compared to the ethnically matched populations. Therefore, further studies are needed in larger cohorts, since it was found only in one heterozygous COVID-19 patient. CONCLUSIONS: Our results suggest that there is no strong evidence, in our cohort, of consistent association of ACE2 variants with COVID-19 severity. We might speculate that rare susceptibility/resistant alleles could be located in the non-coding regions of the ACE2 gene, known to play a role in regulation of the gene activity.

Identification, molecular characterization and segregation analysis of a variant DMPK pre-mutation allele in a three-generation Italian family.

DM1 is an autosomal dominant multisystemic disease caused by an unstable CTG repeat expansion in the 3'-untranslated region (UTR) of the DMPK gene. The complex variant DMPK expanded the alleles containing CAG, CCG, CTC and/or GGC interruptions repetition sequences have been reported in 3-8% of DM1 patients. To date, very few information is available about the frequency and clinical consequences of pre-mutated DMPK variant allele. In this study, we describe a three-generation Italian family showing the segregation of an interrupted DMPK allele within the premutation range. TP-PCR with primers complementary to CCG repetitions and direct sequencing allow us to identify a hetero-triplet (CTG)6(CCGCTG)15(CTG)5 repeat structure. The haplotype analysis demonstrated that this variant allele is associated with the European founder DM1 haplotype. The pyrosequencing analysis of the CpG islands contained in the flanking regions of the CTG array, did not show the presence of a cis effect of the CCG interruptions on the methylation profile of the DM1 locus. The analysis of both meiotic transmissions, one maternal and one paternal, revealed the intrafamilial stability of the DM1 premutation among relatives. Our findings further support the hypothesis of a stabilizing effect of CCG interruptions on the mutational dynamics of the DM1 locus, also in intermediate DMPK alleles.

Cytokine Profile in Striated Muscle Laminopathies: New Promising Biomarkers for Disease Prediction.

Laminopathies are a wide and heterogeneous group of rare human diseases caused by mutations of the LMNA gene or related nuclear envelope genes. The variety of clinical phenotypes and the wide spectrum of histopathological changes among patients carrying an identical mutation in the LMNA gene make the prognostic process rather difficult, and classical genetic screens appear to have limited predictive value for disease development. The aim of this study was to evaluate whether a comprehensive profile of circulating cytokines may be a useful tool to differentiate and stratify disease subgroups, support clinical follow-ups and contribute to new therapeutic approaches. Serum levels of 51 pro- and anti-inflammatory molecules, including cytokines, chemokines and growth factors, were quantified by a Luminex multiple immune-assay in 53 patients with muscular laminopathy (Musc-LMNA), 10 with non-muscular laminopathy, 22 with other muscular disorders and in 35 healthy controls. Interleukin-17 (IL-17), granulocyte colony-stimulating factor (G-CSF) and transforming growth factor beta (TGF-ß2) levels significantly discriminated Musc-LMNA from controls; interleukin-1ß (IL-1ß), interleukin-4 (IL-4) and interleukin-8 (IL-8) were differentially expressed in Musc-LMNA patients compared to those with non-muscular laminopathies, whereas IL-17 was significantly higher in Musc-LMNA patients with muscular and cardiac involvement. These findings support the hypothesis of a key role of the immune system in Musc-LMNA and emphasize the potential use of cytokines as biomarkers for these disorders.

Carrier frequency of CFTR variants in the non-Caucasian populations by genome aggregation database (gnomAD)-based analysis.

The complexity in the molecular diagnosis of Cystic Fibrosis (CF) also depends on the variable prevalence/incidence of the disease associated with the wide CFTR allelic heterogeneity among different populations. In fact, CF incidence in Asian and African countries is underestimated and the few patients reported so far have rare or unique CFTR pathogenic variants. To obtain insights into CF variants profile and frequency, we used the large population sequencing data in the Genome Aggregation Database (gnomAD). We selected 207 CF-causing/varying clinical consequence variants from CFTR2 database and additional 15 variants submitted to the ClinVar database. Only 14 of these variants were found in the East-Asian population, while for South-Asian and African populations we identified 43 and 52 variants, respectively, confirming the peculiarity of the CFTR allelic spectrum with only few population-specific variants. These data could be used to optimize CFTR carrier screening in non-Caucasian subjects, choosing between the full gene sequencing and cost and time-effective targeted panels.

European lipodystrophy registry: background and structure.

BACKGROUND: Lipodystrophy syndromes comprise a group of extremely rare and heterogeneous diseases characterized by a selective loss of adipose tissue in the absence of nutritional deprivation or catabolic state. Because of the rarity of each lipodystrophy subform, research in this area is difficult and international co-operation mandatory. Therefore, in 2016, the European Consortium of Lipodystrophies (ECLip) decided to create a registry for patients with lipodystrophy. RESULTS: The registry was build using the information technology Open Source Registry System for Rare Diseases in the EU (OSSE), an open-source software and toolbox. Lipodystrophy specific data forms were developed based on current knowledge of typical signs and symptoms of lipodystrophy. The platform complies with the new General Data Protection Regulation (EU) 2016/679 by ensuring patient pseudonymization, informational separation of powers, secure data storage and security of communication, user authentication, person specific access to data, and recording of access granted to any data. Inclusion criteria are all patients with any form of lipodystrophy (with the exception of HIV-associated lipodystrophy). So far 246 patients from nine centres (Amsterdam, Bologna, Izmir, Leipzig, Münster, Moscow, Pisa, Santiago de Compostela, Ulm) have been recruited. With the help from the six centres on the brink of recruitment (Cambridge, Lille, Nicosia, Paris, Porto, Rome) this number is expected to double within the next one or 2 years. CONCLUSIONS: A European registry for all patients with lipodystrophy will provide a platform for improved research in the area of lipodystrophy. All physicians from Europe and neighbouring countries caring for patients with lipodystrophy are invited to participate in the ECLip Registry. STUDY REGISTRATION: ClinicalTrials.gov (NCT03553420). Registered 14 March 2018, retrospectively registered.

Cutaneous and metabolic defects associated with nuclear abnormalities in a transgenic mouse model expressing R527H lamin A mutation causing mandibuloacral dysplasia type A (MADA) syndrome.

LMNA gene encodes for lamin A/C, attractive proteins linked to nuclear structure and functions. When mutated, it causes different rare diseases called laminopathies. In particular, an Arginine change in Histidine in position 527 (p.Arg527His) falling in the C-terminal domain of lamin A precursor form (prelamin A) causes mandibuloacral dysplasia Type A (MADA), a segmental progeroid syndrome characterized by skin, bone and metabolic anomalies. The well-characterized cellular models made difficult to assess the tissue-specific functions of 527His prelamin A. Here, we describe the generation and characterization of a MADA transgenic mouse overexpressing 527His LMNA gene, encoding mutated prelamin A. Bodyweight is slightly affected, while no difference in lifespan was observed in transgenic animals. Mild metabolic anomalies and thinning and loss of hairs from the back were the other observed phenotypic MADA manifestations. Histological analysis of tissues relevant for MADA syndrome revealed slight increase in adipose tissue inflammatory cells and a reduction of hypodermis due to a loss of subcutaneous adipose tissue. At cellular levels, transgenic cutaneous fibroblasts displayed nuclear envelope aberrations, presence of prelamin A, proliferation, and senescence rate defects. Gene transcriptional pattern was found differentially modulated between transgenic and wildtype animals, too. In conclusion, the presence of 527His Prelamin A accumulation is further linked to the appearance of mild progeroid features and metabolic disorder without lifespan reduction.

Long term breeding of the Lmna G609G progeric mouse: Characterization of homozygous and heterozygous models.

The transgenic LmnaG609G progeric mouse represents an outstanding animal model for studying the human Hutchinson-Gilford Progeria Syndrome (HGPS) caused by a mutation in the LMNA gene, coding for the nuclear envelope protein Lamin A/C, and, as an important, more general scope, for studying the complex process governing physiological aging in humans. Here we give a comprehensive description of the peculiarities related to the breeding of LmnaG609G mice over a prolonged period of time, and of many features observed in a large colony for a 2-years period. We describe the breeding and housing conditions underlining the possible interference of the genetic background on the phenotype expression. This information represents a useful tool when planning and interpreting studies on the LmnaG609G mouse model, complementing any specific data already reported in the literature about this model since its production. It is also particularly relevant for the heterozygous mouse, which mirrors the genotype of the human pathology however requires an extended time to manifest symptoms and to be carefully studied.