Hutchinson-Gilford progeria syndrome: report of a Libyan family and evidence of autosomal recessive inheritance

Generation of a Hutchinson-Gilford progeria syndrome monkey model by base editing

Many human genetic diseases, including Hutchinson-Gilford progeria syndrome (HGPS), are caused by single point mutations. HGPS is a rare disorder that causes premature aging and is usually caused by a de novo point mutation in the LMNA gene. Base editors (BEs) composed of a cytidine deaminase fused to CRISPR/Cas9 nickase are highly efficient at inducing C to T base conversions in a programmable manner and can be used to generate animal disease models with single amino-acid substitutions. Here, we generated the first HGPS monkey model by delivering a BE mRNA and guide RNA (gRNA) targeting the LMNA gene via microinjection into monkey zygotes. Five out of six newborn monkeys carried the mutation specifically at the target site. HGPS monkeys expressed the toxic form of lamin A, progerin, and recapitulated the typical HGPS phenotypes including growth retardation, bone alterations, and vascular abnormalities. Thus, this monkey model genetically and clinically mimics HGPS in humans, demonstrating that the BE system can efficiently and accurately generate patient-specific disease models in non-human primates.

Hutchinson-Gilford Progeria Syndrome: A Premature Aging Disease

Progeria is sporadic, very rare, autosomal dominant, deadly childhood disorder. It is one of the progeroid syndromes also known as Hutchinson-Gilford progeria syndrome (HGPS). Aging is a developmental process that begins with fertilization and ends up with death involving a lot of environmental and genetic factors. The disease firstly involves premature aging and then death from complications of atherosclerosis such as myocardial infarction, stroke, atherosclerosis, or heart failure. The lifespan of the patient is normally up to teen age or early twenties. It is usually not inherited because a patient normally dies before the age of reproduction. The most important genetic linkage between progeria and aging is shortening of telomere ends with each replication cycle. The patients are normally observed to have extremely short telomeres. Currently, 90% of the patients are said to have de novo point mutations in the LMNA gene that substitute cytosine with thymine and have been found in individuals with HGPS. Lmna encodes lamins A and C, and the A-type lamins have important structural function in the nuclear envelope. The most common type of HGPS mutation is located at codon 608 (G608G). It could not be diagnosed at birth, but after the age of 2 years, visible, prominent symptoms can be observed. Still, lot of research is needed to solve this mystery; hopefully, future research on HGPS would provide important clues for progeria and other fatal age-related disorders.

Hutchinson-gilford progeria syndrome: a rare genetic disorder

Hutchinson-Gilford progeria syndrome (HGPS) is a rare pediatric genetic syndrome with incidence of one per eight million live births. The disorder is characterised by premature aging, generally leading to death at approximately 13.4 years of age. This is a follow-up study of a 9-year-old male with clinical and radiographic features highly suggestive of HGPS and presented here with description of differential diagnosis and dental consideration. This is the first case report of HGPS which showed pectus carinatum structure of chest.

Hutchinson-Gilford progeria syndrome accompanied by severe skeletal abnormalities in two Chinese siblings: two case reports

Introduction

Hutchinson-Gilford progeria syndrome is a rare pediatric genetic syndrome with an incidence of one per eight million live births. The disorder is characterized by premature aging, generally leading to death due to myocardial infarction or stroke at approximately 13.4 years of age. The genetic diagnosis and special clinical manifestation in two Han Chinese siblings observed at our clinic for genetic counseling are described in this report. We screened the LMNA gene in these two siblings as well as in their unaffected parents. A homozygous mutation R527C was identified in the affected siblings, and both parents were heterozygous for this variant.

Case presentation

In case 1, the elder 10-year-old female sibling showed the classic physical and radiological changes of Hutchinson-Gilford progeria syndrome in addition to a considerable overlap with the phenotype of mandibuloacral dysplasia.

In case 2, the younger male sibling had begun to show some early physical changes at age six months.

Conclusion

The phenotypic findings in the patients we describe here widen the clinical spectrum of Hutchinson-Gilford progeria syndrome symptoms, providing further recognition of the phenotypic range of LMNA-associated diseases.

Progeria in siblings: a rare case report

Progeria, also known as Hutchinson-Gilford syndrome, is an extremely rare, severe genetic condition wherein symptoms resembling aspects of aging are manifested at an early age. It is an autosomal dominant disorder. It is not seen in siblings of affected children although there are very few case reports of progeria affecting more than one child in a family. Here we are presenting two siblings, a 14-year-old male and a 13-year-old female with features of progeria, suggesting a possible autosomal recessive inheritance.

A translational view of the genetics of lipodystrophy and ectopic fat deposition

A wide range of lipodystrophy syndromes exist, each with varying clinical presentations, and yet cumulatively they underscore the importance of adipocyte biology in human metabolism. Loss of the ability to retain excess lipids in "classical" adipose tissue stores can lead to the overdevelopment of ectopic fat stores, often creating severe perturbations of both glucose and lipid homeostasis. Linkage analysis and candidate sequencing efforts have successfully identified responsible mutations for multiple forms of lipodystrophy. Recently, the reduction in the cost of DNA sequencing has resulted in discovery of many novel mutations within both known and novel loci. In this review, we present the steps involved in clinical characterization of a suspected lipodystrophy case, an overview of the clinical manifestations, molecular findings, and pathogenic basis of different forms of lipodystrophy, a discussion of therapeutic options for lipodystrophy patients, and an examination of genetic advances that will be used to identify additional pathogenic mechanisms.

The posttranslational processing of prelamin A and disease

Human geneticists have shown that some progeroid syndromes are caused by mutations that interfere with the conversion of farnesyl-prelamin A to mature lamin A. For example, Hutchinson-Gilford progeria syndrome is caused by LMNA mutations that lead to the accumulation of a farnesylated version of prelamin A. In this review, we discuss the posttranslational modifications of prelamin A and their relevance to the pathogenesis and treatment of progeroid syndromes.

Homozygous LMNA mutation R527C in atypical Hutchinson-Gilford progeria syndrome: evidence for autosomal recessive inheritance

AIM

To describe two Chinese siblings of atypical Hutchinson-Gilford progeria syndrome (HGPS), with genetic diagnosis and special clinical manifestation.

METHODS

We screened the LMNA gene in four members of a consanguineous family, in which two children were suffering from atypical HGPS. Besides general HGPS features, such as growth retardation and characteristic appearance, special clinical phenotypes including disorders of digestive system and severe skeletal damages were observed.

RESULTS

Homozygous mutation 1579C>T, which predicts R527C, was identified in the exon 9 of LMNA among the affected siblings. Heterozygous carrier status 1579C>T was detected in both of the asymptomatic parents.

CONCLUSION

Homozygous mutation R527C in LMNA yields atypical HGPS, and it suggests an autosomal recessive inheritance in this family.

New approaches to progeria

Progeria (Hutchinson-Gilford progeria syndrome) is a rare genetic disorder that offers considerable insight into the biology of premature aging. This review summarizes the clinical characteristics of this disease and the underlying mutation in the lamin A (LMNA) gene that results in this phenotype. Modifications in the processing of prelamin A through alterations in farnesylation are detailed, because this pathway offers a possible drug target. Finally, discussion of an ongoing clinical trial for these children, including possible parameters for evaluation, are discussed. In the span of less than a decade, this disease has progressed from an interesting phenotype to one in which the gene defect has been identified, animal models have been created and tested with drugs that target the primary disease pathway, and significant clinical baseline data for the support of a clinical trial have been obtained.

Hutchinson-Gilford progeria syndrome: review of the phenotype

Hutchinson-Gilford progeria syndrome (HGPS) is a rare but well known entity characterized by extreme short stature, low body weight, early loss of hair, lipodystrophy, scleroderma, decreased joint mobility, osteolysis, and facial features that resemble aged persons. Cardiovascular compromise leads to early demise. Cognitive development is normal. Data on 10 of our own cases and 132 cases from literature are presented. The incidence in the last century in the Netherlands was 1:4,000,000. Sex ratio was 1.2:1. Main first symptoms were failure to thrive (55%), hair loss (40%), skin problems (28%), and lipodystrophy (20%). Mean age at diagnosis was 2.9 years. Growth in weight was more disturbed than growth in height, and growth delay started already prenatally. Mean height > 13 years was 109.0 cm, mean weight was 14.5 kg. Osteolysis was wide-spread but not expressed, except in the viscerocranium, and remained limited to membranous formed bone. Lipodystrophy is generalized, only intra-abdominal fat depositions remain present. Cardiovascular problems are extremely variable, both in age of onset and nature. Stroke and coronary dysfunctioning are most frequent. Pathologic findings in coronaries and aorta resemble sometimes the findings in elderly persons, but can also be much more limited. Loss of smooth muscle cells seems the most important finding. Mean age of demise was 12.6 years. Patients can be subdivided in patients with classical HGPS, which follows an autosomal dominant pattern of inheritance, (almost) all cases representing spontaneous mutations, and in non-classical progeria, in whom growth can be less retarded, scalp hair remains present for a longer time, lipodystrophy is more slowly progressive, osteolysis is more expressed except in the face, and survival well into adulthood is not uncommon. Pattern of inheritance of non-classical progeria is most probably autosomal recessive. The cause of HGPS is an abnormally formed Lamin A, either directly by a mutated LMNA gene, or through abnormal posttranslational processing (ZMPSTE24 gene mutations). Of 34 LMNA mutations found in progeria patients, there were 26 classical p.G608G mutations (76%). Pathogenesis is most likely to follow several different pathways. Potential therapeutic strategies are developed along these lines and include RNA interference techniques and inhibition of the dominant-negative influence of abnormally formed Lamin A on polymerization with normally formed Lamin A.

Altered splicing in prelamin A-associated premature aging phenotypes

Hutchinson-Gilford progeria (HGPS), a rare and severe developmental disorder characterized by features recalling premature aging, and restrictive dermopathy (RD), a neonatal lethal genodermatosis, have recently been identified as being primary or secondary "laminopathies." These are heterogeneous disorders due to altered function of lamins A/C or related proteins. In physiological conditions, mature lamin A is obtained through a series of post-translational processing steps performed on a protein precursor, prelamin A. The major pathophysiological mechanism involved in progeria is an aberrant splicing of pre-mRNAs issued from the LMNA gene, due to a de novo heterozygous point mutation, leading to the production and accumulation of truncated lamin A precursors. Aberrant splicing of prelamin A pre-mRNAs causing the production of more extensively truncated precursors is involved in the allelic disease restrictive dermopathy. Other restrictive dermopathy cases are due to the inactivation of a key enzyme involved in the maturation of lamin A precursors (ZMPSTE24). In functional terms, all these conditions share the same pathophysiological basis: intranuclear accumulation of lamin A precursors, which cannot be fully processed (due to primary or secondary events) and exert toxic, dominant negative effects on nuclear homeostasis. Most other laminopathies are due to autosomal dominant LMNA point mutations inferred to cause single amino acid substitutions. In any case, the impact of these mutations on pre-mRNA splicing has rarely been assessed. These disorders affect different tissues and organs, mainly including bone, skin, striated muscles, adipose tissue, vessels, and peripheral nerves in isolated or combined fashions, giving rise to syndromes whose severity ranges from mild to perinatally lethal. In this chapter we review the structure and functions of lamins A/C in physiological and pathological conditions, describe their known or putative roles, namely, in the pathogenesis of HGPS and RD in relation to existing animal models, and envisage possible targeted therapeutic strategies on the basis of recent research results.

Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare genetic disorder that causes premature, rapid aging shortly after birth. Recently, de novo point mutations in the Lmna gene have been found in individuals with HGPS. Lmna encodes lamin A and C, the A-type lamins, which are an important structural component of the nuclear envelope. The most common HGPS mutation is located at codon 608 (G608G). This mutation creates a cryptic splice site within exon 11, which deletes a proteolytic cleavage site within the expressed mutant lamin A. Incomplete processing of prelamin A results in nuclear lamina abnormalities that can be observed in immunofluorescent studies of HGPS cells. Mouse models, such as Lmna knockout, Zmpste24 knockout, and Lmna L530P knockin will help the study of progeria. Lmna mutations have also recently been found in patients with atypical forms of progeria. The discovery of the HGPS mutations brings the total number of diseases caused by mutant Lmna to nine, underscoring the astonishing spectrum of laminopathies. Future research into HGPS could also provide important clues about the general process of aging and aging-related diseases.

Somatic and gonadal mosaicism in Hutchinson-Gilford progeria

We have studied a patient with Hutchinson-Gilford progeria (HGP). Sequence analysis of the LMNA gene demonstrated the presence of a c.1824 C > T (p.G608G) mutation, activating a cryptic splice donor site and leading to the formation of a truncated Lamin A protein. All molecularly characterized autosomal dominant HGP cases described so far result from de novo LMNA mutations, mostly originating on the paternal allele and are often linked with advanced paternal age. However, in our patient, the mutation was transmitted by the mother who showed somatic and germline mosaicism without HGP manifestations.

Recurrent de novo point mutations in lamin A cause Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder characterized by features reminiscent of marked premature ageing. Here, we present evidence of mutations in lamin A (LMNA) as the cause of this disorder. The HGPS gene was initially localized to chromosome 1q by observing two cases of uniparental isodisomy of 1q-the inheritance of both copies of this material from one parent-and one case with a 6-megabase paternal interstitial deletion. Sequencing of LMNA, located in this interval and previously implicated in several other heritable disorders, revealed that 18 out of 20 classical cases of HGPS harboured an identical de novo (that is, newly arisen and not inherited) single-base substitution, G608G(GGC > GGT), within exon 11. One additional case was identified with a different substitution within the same codon. Both of these mutations result in activation of a cryptic splice site within exon 11, resulting in production of a protein product that deletes 50 amino acids near the carboxy terminus. Immunofluorescence of HGPS fibroblasts with antibodies directed against lamin A revealed that many cells show visible abnormalities of the nuclear membrane. The discovery of the molecular basis of this disease may shed light on the general phenomenon of human ageing.

Progeria infantum (Hutchinson-Gilford syndrome) associated with scleroderma-like lesions and acro-osteolysis: a case report and brief review of the literature

Progeria infantum (Hutchinson-Gilford syndrome) is a very rare syndrome of premature aging characterized by growth retardation and specific, progressive, premature senescent changes of the skin and other tissues. We report a 1.5-year-old girl with loss of scalp hair, eyebrows, and lashes, prominent scalp veins, micrognathia, abnormal ears, loss of subcutaneous tissue, and scleroderma-like areas over the trunk. Radiographic studies revealed coxa valga and acro-osteolysis of the terminal phalanges. The clinical and radiologic features corresponded well with progeria infantum.

Progeria: medical aspects, psychosocial perspectives, and intervention guidelines

This article discusses progeria, a rare genetic childhood disorder that invariably results in the individual's death during early adolescence. The article begins by describing the major medical aspects of progeria. This is followed by a discussion of the psychosocial implications of the disorder with particular emphasis upon grief-triggered reactions. The article concludes with an overview of psychosocial intervention guidelines for caregivers who work with families of dying children and adolescents.

The mitochondrial F1-ATPase and the aging process

A progressive dysfunction of the mitochondrion probably plays a decisive role in the aging process. In the present hypothesis it is suggested that the functional defect specifically concerns the catalytic subunit of the mitochondrial F1-ATPase. This proposal is based on observations concerning two classical models of the aging process. 1. The Werner syndrome of premature aging is autosomally recessive; meaning that this disorder--in analogy with other recessive inborn errors of metabolism--results from a single specific mutation, typically resulting in an enzyme defect. 2. The strong association between the ATPase activity of the SV40 T-antigen and the process of cellular immortalization in vitro, suggests that the putative enzyme dysfunction could concern an ATPase. The decrease with aging in the activity of the mitochondrial F1-ATPase--the main producer of ATP--could lay behind the progressive lack of homeostasis observed in senescence.

Progressive early dermatologic changes in Hutchinson-Gilford progeria syndrome

We describe evolving dermatologic findings in a male with progeria from age 1 month to 21.5 months. At 18 months of age, irregular pigmentary changes of the abdomen, early occipital alopecia, superficial scalp veins, glyphic nasal tip, absent ear lobules, coarse hair that stands on end, crowded dentition with delayed tooth development, and dystrophic nails permitted the diagnosis of progeria. Radiographs showed evidence of resorption of the distal ends of the clavicles, attenuation of the terminal phalanges, diffuse osteopenia, and fishmouth vertebral bodies, which are typical of this syndrome. Appreciation of the evolution of early dermatologic findings may permit earlier diagnosis of this condition in infants with skin changes.

Reduced DNA-repair capacity in cells originating from a progeria patient

A Chinese boy was identified to be suffering from progeria (Hutchinson-Gilford syndrome), the first case of the disease ever reported in China. Cells originating from the patient had a reduced amount of unscheduled DNA synthesis after irradiation with ultraviolet light (UV). The fractions of the progeria cells surviving against UV irradiation measured by colony-forming ability, and the host-cell reactivation capacity of the progeria cells, measured by the plaque formation of UV-irradiated herpes simplex virus were lower than those measured in normal cells. The progeria cells appear to have a reduced capacity to repair UV excision damage.