-
Animal Genetics Oct 2023Hypertrophic cardiomyopathy (HCM) is the most common cardiomyopathy in domestic cats, and some inherited variants are available for genetic testing. A variant of the...
Hypertrophic cardiomyopathy (HCM) is the most common cardiomyopathy in domestic cats, and some inherited variants are available for genetic testing. A variant of the Alstrom syndrome protein 1 gene (ALMS1) was recently reported to be associated with HCM in the Sphynx cat breed (A3: g.92439157G>C). Genetic screening of the variant, promoted by the Osservatorio Veterinario Italiano Cardiopatie and Genefast Laboratory, was offered to Sphynx cat owners and breeders in Italy. Genotype data were initially obtained by Sanger sequencing. In one case where the samples of a trio were available, inconsistency in the vertical transmission of the variant suggested an allele dropout (ADO) of the wt allele. A new external primer pair was designed as an alternative to the original. The larger PCR product obtained was sanger sequenced, and five novel single nucleotide variants (SNVs) not yet annotated in open-access databases were detected. Three of these SNVs were within the original primer-binding regions and were assumed to have caused ADO. The haplotype, including the ADO SNVs, was detected in two cats belonging to different lineages. To accurately genotype ALMS1 g.92439157G>C in the samples, we set up a real-time TaqMan MGB assay while avoiding all surrounding SNVs. At g.92439157G>C, for 136 Sphynx cats, g.92439157 C variant was highly widespread (freq. >0.50). The present study reports five new variants surrounding ALMS1 g.92439157G>C that must be considered when designing the test. The study also indicates the need to verify the correspondence between the g.92439157 C variant frequency and the prevalence of HCM by increasing clinical visits and follow-ups and finally to promote genetic counselling for accurate management of mating plans in Italian Sphynx cats.
Topics: Cats; Animals; Alleles; Cardiomyopathy, Hypertrophic; Genotype; Base Sequence; Italy; Cat Diseases
PubMed: 37345275
DOI: 10.1111/age.13340 -
Journal of Medical Genetics Dec 2023Alström syndrome (ALMS; #203800) is an ultrarare monogenic recessive disease. This syndrome is associated with variants in the gene, which encodes a... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Alström syndrome (ALMS; #203800) is an ultrarare monogenic recessive disease. This syndrome is associated with variants in the gene, which encodes a centrosome-associated protein involved in the regulation of several ciliary and extraciliary processes, such as centrosome cohesion, apoptosis, cell cycle control and receptor trafficking. The type of variant associated with ALMS is mostly complete loss-of-function variants (97%) and they are mainly located in exons 8, 10 and 16 of the gene. Other studies in the literature have tried to establish a genotype-phenotype correlation in this syndrome with limited success. The difficulty in recruiting a large cohort in rare diseases is the main barrier to conducting this type of study.
METHODS
In this study we collected all cases of ALMS published to date. We created a database of patients who had a genetic diagnosis and an individualised clinical history. Lastly, we attempted to establish a genotype-phenotype correlation using the truncation site of the patient's longest allele as a grouping criteria.
RESULTS
We collected a total of 357 patients, of whom 227 had complete clinical information, complete genetic diagnosis and meta-information on sex and age. We have seen that there are five variants with high frequency, with p.(Arg2722Ter) being the most common variant, with 28 alleles. No gender differences in disease progression were detected. Finally, truncating variants in exon 10 seem to be correlated with a higher prevalence of liver disorders in patients with ALMS.
CONCLUSION
Pathogenic variants in exon 10 of the gene were associated with a higher prevalence of liver disease. However, the location of the variant in the gene does not have a major impact on the phenotype developed by the patient.
Topics: Humans; Alstrom Syndrome; Cell Cycle Proteins; Phenotype; Exons; Genetic Association Studies
PubMed: 37321834
DOI: 10.1136/jmg-2023-109175 -
Proceedings of the National Academy of... Jun 2023Retinitis pigmentosa (RP) is an ocular disease characterized by the loss of night vision, followed by the loss of daylight vision. Daylight vision is initiated in the...
Retinitis pigmentosa (RP) is an ocular disease characterized by the loss of night vision, followed by the loss of daylight vision. Daylight vision is initiated in the retina by cone photoreceptors, which are gradually lost in RP, often as bystanders in a disease process that initiates in their neighboring rod photoreceptors. Using physiological assays, we investigated the timing of cone electroretinogram (ERG) decline in RP mouse models. A correlation between the time of loss of the cone ERG and the loss of rods was found. To investigate a potential role of the visual chromophore supply in this loss, mouse mutants with alterations in the regeneration of the retinal chromophore, 11- retinal, were examined. Reducing chromophore supply via mutations in or resulted in greater cone function and survival in a RP mouse model. Conversely, overexpression of and , genes that can drive the regeneration of the chromophore, led to greater cone degeneration. These data suggest that abnormally high chromophore supply to cones upon the loss of rods is toxic to cones, and that a potential therapy in at least some forms of RP is to slow the turnover and/or reduce the level of visual chromophore in the retina.
Topics: Mice; Animals; Retina; Retinal Cone Photoreceptor Cells; Retinal Rod Photoreceptor Cells; Retinitis Pigmentosa; Color Vision; Disease Models, Animal
PubMed: 37252956
DOI: 10.1073/pnas.2217885120 -
PloS One 2023Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats with a suspected genetic origin. Previous studies have identified five HCM-associated variants...
Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats with a suspected genetic origin. Previous studies have identified five HCM-associated variants in three genes (Myosin binding protein C3: MYBPC3 p.A31P, p.A74T, p.R820W; Myosin heavy chain 7: MYH7 p.E1883K; Alstrom syndrome protein 1: ALMS1 p.G3376R). These variants are considered breed-specific, with the exception of MYBPC3 p.A74T, and have rarely been found in other breeds. However, genetic studies on HCM-associated variants across breeds are still insufficient because of population and breed bias caused by differences in genetic background. This study investigates the ubiquitous occurrence of HCM-associated genetic variants among cat breeds, using 57 HCM-affected, 19 HCM-unaffected, and 227 non-examined cats from the Japanese population. Genotyping of the five variants revealed the presence of MYBPC3 p.A31P and ALMS1 p.G3376R in two (Munchkin and Scottish Fold) and five non-specific breeds (American Shorthair, Exotic Shorthair, Minuet, Munchkin and Scottish Fold), respectively, in which the variants had not been identified previously. In addition, our results indicate that the ALMS1 variants identified in the Sphynx breed might not be Sphynx-specific. Overall, our results suggest that these two specific variants may still be found in other cat breeds and should be examined in detail in a population-driven manner. Furthermore, applying genetic testing to Munchkin and Scottish Fold, the breeds with both MYBPC3 and ALMS1 variants, will help prevent the development of new HCM-affected cat colonies.
Topics: Cats; Animals; Japan; Carrier Proteins; Cardiomyopathy, Hypertrophic; Cytoskeletal Proteins; Health Status; Mutation
PubMed: 37071642
DOI: 10.1371/journal.pone.0283433 -
Yi Chuan = Hereditas Dec 2022Alstrom syndrome is a rare autosomal recessive disorder disease caused by mutations in the gene, and its typical clinical manifestations include cone-rod retinal...
Alstrom syndrome is a rare autosomal recessive disorder disease caused by mutations in the gene, and its typical clinical manifestations include cone-rod retinal dystrophy, sensorineural deafness, obesity, insulin resistance, diabetes mellitus, hypertriglyceridemia, non-alcoholic fatty liver, dilated cardiomyopathy, and progressive hepatic and renal dysfunction. In this report, we followed up a young male patient presenting with diabetes mellitus, who was later diagnosed with blindness, deafness, hyperlipidemia, obesity, fatty liver, and insulin resistance. Genetic testing revealed a compound heterozygous mutation in from the patient, with an exon 8 c.5535delG (p.S1847Lfs*24) mutation inherited from the maternal side and an exon 16 c.10819C>T (p.R3607X) mutation from the paternal side. Neither of these two mutations had been previously recorded in the known genetic mutation database. Hyperinsulinemic-euglycemic clamp test indicated that the insulin sensitivity index was significantly improved in the patient after taking oral dapagliflozin. By summarizing and analyzing this case, we should consider Alstrom syndrome in clinical adolescent-onset diabetes patients with blindness, deafness, severe insulin resistance, and lipid metabolism disorder. These two new mutation sites identified in this case enrich the genetic mutation database of the gene, and the follow-up data of this study provide new evidence for deciding appropriate glucose-lowering regimens in patients with Alstrom syndrome.
Topics: Adolescent; Humans; Male; Alstrom Syndrome; Cell Cycle Proteins; Insulin Resistance; Mutation; Obesity; Diabetes Mellitus; Blindness; Fatty Liver; Deafness
PubMed: 36927560
DOI: 10.16288/j.yczz.22-217 -
Clinical Case Reports Feb 2023Alstrom syndrome is a rare genetic disorder with an autosomal recessive mutation in the ALMS1 gene. The disease's manifestations include ophthalmic problems, hearing...
Alstrom syndrome is a rare genetic disorder with an autosomal recessive mutation in the ALMS1 gene. The disease's manifestations include ophthalmic problems, hearing loss, obesity, and cardiovascular disorders. In addition, medical cases include other organ complications. However, the overlapping variety of such symptoms with other diseases may delay the diagnosis. In this article, we describe the case of a 7-year-old female patient with Alstrom syndrome, and cardiovascular and hyperphenylalaninemia diseases since birth. Other symptoms included diabetes and ophthalmologic problems with skeletal disability. Blindness and hearing impairment were diagnosed, along with recurrence of respiratory problems at the age of 7 years. The patient's obesity-induced snoring predisposed her to uncontrolled blood glucose. In fact, respiratory tract problems and sleep disorders had occurred as a degraded cycle and left her with a severe disability for years. The similarity of the symptoms with other diseases had misled the physician in diagnosis. However, a polysomnography test (because of complaints of short sleep duration) recognized the source of the patient's sleep disorders and breathing problems. Eventually, we delivered a portable ventilator to the child for continuous positive airway pressure (CPAP) therapy. The child's breathing and oxygenation conditions improved. Using the ventilator and the CPAP system, we discharged her from the hospital without requiring oxygenation, in a stable condition. The procedure could prevent the patient from hypoxia and retinal problem.
PubMed: 36777792
DOI: 10.1002/ccr3.6894 -
Nephron 2024We describe the unique case of a patient in whom two ciliopathies with autosomal recessive transmission were clinically and molecularly diagnosed: nephronophthisis type...
We describe the unique case of a patient in whom two ciliopathies with autosomal recessive transmission were clinically and molecularly diagnosed: nephronophthisis type 1 (NPHP1) and Alström syndrome (AS). NPHP1 is one of the main genetic causes of terminal kidney failure in childhood. AS is an ultra-rare multi-systemic disease, characterized by progressive kidney disease, hepatic failure, dystrophy of the rods and cones to blindness, slowly progressive neuro-sensory deafness, dilated cardiomyopathy, obesity, insulin resistance/type 2 diabetes mellitus. The coexistence in the same patient of two rare syndromes with overlapping clinical manifestations but genetically different is an eventuality to be considered. This case report would describe the onset and progression of the multi-organ manifestations of both syndromes to highlight that ciliopathies present a strong phenotype overlap but also specific peculiarities. Therefore, to make a correct diagnosis that is essential to achieve the best clinical management could be challenging.
Topics: Humans; Alstrom Syndrome; Kidney Diseases, Cystic; Male; Female; Membrane Proteins; Adaptor Proteins, Signal Transducing; Cytoskeletal Proteins
PubMed: 36746137
DOI: 10.1159/000529473 -
Endocrinology Jan 2023Alström syndrome (AS) is a rare genetic disease caused by ALMS1 mutations, characterized by short stature, and vision and hearing loss. Patients with AS develop the...
Alström syndrome (AS) is a rare genetic disease caused by ALMS1 mutations, characterized by short stature, and vision and hearing loss. Patients with AS develop the metabolic syndrome, long-term organ complications, and die prematurely. We explored the association between AS and a shortage of hematopoietic stem/progenitor cells (HSPCs), which is linked to metabolic diseases and predicts diabetic complications. We included patients with AS at a national referral center. We measured HSPCs with flow cytometry at baseline and follow-up. We followed patients up to January 2022 for metabolic worsening and end-organ damage. We evaluated HSPC levels and mobilization as well as bone marrow histology in a murine model of AS. In 23 patients with AS, we found significantly lower circulating HSPCs than in healthy blood donors (-40%; P = .002) and age/sex-matched patients (-25%; P = .022). Longitudinally, HSPCs significantly declined by a further 20% in patients with AS over a median of 36 months (interquartile range 30-44). Patients with AS who displayed metabolic deterioration over 5.3 years had lower levels of HSPCs, both at baseline and at last observation, than those who did not deteriorate. Alms1-mutated mice were obese and insulin resistant and displayed significantly reduced circulating HSPCs, despite no overt hematological abnormality. Contrary to what was observed in diabetic mice, HSPC mobilization and bone marrow structure were unaffected. We found depletion of HSPCs in patients with AS, which was recapitulated in Alms1-mutated mice. Larger and longer studies will be needed to establish HSPCs shortage as a driver of metabolic deterioration leading to end-organ damage in AS.
Topics: Animals; Mice; Metabolic Syndrome; Alstrom Syndrome; Diabetes Mellitus, Experimental; Models, Genetic; Bone Marrow Cells; Hematopoietic Stem Cells
PubMed: 36702623
DOI: 10.1210/endocr/bqad011 -
Cureus Dec 2022We report a case of a five-month-old girl, who presented to our hospital with increased work of breathing, sweating since birth, and abnormal eye movements. On further...
We report a case of a five-month-old girl, who presented to our hospital with increased work of breathing, sweating since birth, and abnormal eye movements. On further evaluation, she was found to have restrictive cardiomyopathy, nystagmus, and hypotonia. Genetic workup showed a pathogenic variant in the ALSM1 gene, which confirmed the diagnosis of Alström syndrome. Alström syndrome is a rare condition that is characterized by a wide variety of multisystem manifestations, including visual disturbances, hearing impairment, and cardiomyopathy. This case report highlights Alström syndrome as one of the rare causes of early-onset infantile cardiomyopathy with nystagmus.
PubMed: 36694529
DOI: 10.7759/cureus.32857 -
Frontiers in Genetics 2022Alström syndrome (AS) is a rare autosomal recessive disorder caused by variants of . The objectives of this study were to describe the clinical and genetic...
Alström syndrome (AS) is a rare autosomal recessive disorder caused by variants of . The objectives of this study were to describe the clinical and genetic characteristics of 19 Chinese patients with biallelic variants in . We recruited 19 probands with biallelic disease-causing variants. All patients underwent ophthalmic and systematic evaluations and comprehensive molecular genetic analysis. Reverse transcriptase-polymerase chain reaction (RT-PCR) assays were performed to observe the effect of a novel missense variant on pre-mRNA splicing. We identified 33 causative variants in , including 15 frameshift small indels, 14 non-sense variants, two gross deletions, one splicing variant, and one missense variant. RT-PCR showed that the missense variant c.9542G>A (p.R3181Q) altered pre-mRNA splicing to generate a truncated protein p. (Ser3082Asnfs*6). Retinal dystrophy (RD) was noted in all the patients, followed by metabolism disturbance (obesity or acanthosis nigricans) in 66.7% and hearing impairment in 61.1% of the patients. Patient systemic symptom numbers and their age at evaluation showed a significant positive correlation, and BCVA and age at the last examination showed a moderate correlation. All patients exhibited early-onset RD and severe visual impairment. The exception was one patient carrying homozygous p. R3181Q, who showed a mild visual defect and atypical retinal phenotype. Our findings expand the pathogenic variant spectrum of and provide the first verification of a novel missense variant caused AS by aberrant pre-mRNA splicing. Patients with AS might demonstrate varied clinical spectra; therefore, genetic analysis is vital for the early and accurate diagnosis of patients with atypical AS.
PubMed: 36685911
DOI: 10.3389/fgene.2022.1104420