Rare Genetic Kidney Diseases: Windows of Precision Nephrology / 罕见病研究

As an important category of rare diseases, rare genetic kidney diseases have many types. In recent years, their diagnosis, treatment, research and management strategies have made great progress. Continuously more new genes and mechanisms have been discovered, giving rise to new technologies and drugs for precision medicine and clinical applications. This article systematically analyzes rare diseases involving the urinary system listed in the catalog of rare diseases in China, gives examples to illustrate the research and management methods for the diagnosis and treatment of rare genetic kidney diseases, promotes clinical applications of new drugs by expanding physiological mechanisms, introduces the application of special blood purification in the field of critical rare diseases, and provides an outlook forward to the future prospects of precise diagnosis and treatment of rare kidney diseases in China.

Autoinflammatory diseases: a Latin American multicenter study according to age and sex / Doenças autoinflamatórias: um estudo multicêntrico latino-americano de acordo com o sexo e a idade

ABSTRACT Objective: To evaluate autoinflammatory diseases (AID) according to age at diagnosis and sex, and response to therapy in a large population. Methods: This is a cross-sectional observational study of a Latin American registry using a designed web system for data storage, collected between 2015 and 2018. Any altered findings during follow-up were recorded. The forms were translated into Portuguese and Spanish, including demographic, clinical, laboratory, genetic and treatment characteristics. Results: We included 152 patients, 51.3% male and 75% Caucasian. The median age at disease onset was 2.1 years (0-15.6 years) and median age at diagnosis 6.9 years (0-21.9 years); 111 (73%) were children (0-9 years old), and 41 (27%) were adolescents and young adults (AYA) (10-21 years old). Periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome (PFAPA) occurred in 46/152 (30%), chronic non-bacterial osteomyelitis (CNO) in 32/152 (21%), and familial Mediterranean fever (FMF) in 24/152 (15.7%). PFAPA was significantly higher in young children than in AYA (38.7% vs. 7.3%, p<0.001), while CNO were lower (13.5% vs. 41.5%, p<0.001). The frequency of females was significantly higher in CNO (28.4% vs. 14.1%, p=0.031) and lower in FMF (8.1% vs. 23.1%, p=0.011). The most used drugs were glucocorticoids, non-steroidal anti-inflammatory drugs (NSAID), and colchicine. Glucocorticoids and colchicine treatment were used in all AID with good to moderate response. However, cryopyrin-associated periodic syndromes (CAPS) seemed unresponsive to glucocorticoids. NSAIDs and methotrexate were the main medications used to treat CNO. Conclusions: Differences among AID patients were observed in the LA population regarding sex and age at disease diagnosis.

RESUMO Objetivo: Avaliar as doenças autoinflamatórias (DAI) de acordo com sexo e idade no momento do diagnóstico e a resposta terapêutica em uma grande população. Métodos: Este é um estudo observacional transversal de um registro latino-americano que usou um sistema de dados coletados entre 2015 e 2018. Quaisquer achados alterados ao longo do acompanhamento foram registrados. Os formulários foram traduzidos para os idiomas português e espanhol, incluindo características demográficas, clínicas, laboratoriais, genéticas e de tratamento. Resultados: Incluímos 152 pacientes, sendo 51,3% do sexo masculino e 75% da raça branca. A média de idade de início da doença foi de 2,1 anos (0-15,6 anos) e a média de idade de diagnóstico 6,9 anos (0-21,9 anos); 111 (73%) eram crianças (0-9 anos) e 41 (27%) adolescentes/adultos jovens (10-21 anos). A síndrome de febre periódica, estomatite aftosa, faringite e adenite (PFAPA) ocorreu em 46/152 (30%), osteomielite não bacteriana crônica (CNO) em 32/152 (21%) e febre familiar do Mediterrâneo (FMF) em 24/152 (15,7%). A PFAPA foi significativamente maior em crianças pequenas (38,7 vs. 7,3%, p<0,001), e a CNO, em adolescentes/adultos jovens (13,5 vs. 41,5%, p<0,001). A frequência do sexo feminino foi significativamente maior na CNO (28,4 vs. 14,1%, p=0,031) e menor na FMF (8,1 vs. 23,1%, p=0,011). Os medicamentos mais utilizados foram glicocorticoides, anti-inflamatórios não esteroidais (AINE) e colchicina. O tratamento com glicocorticoides e colchicina foi usado em todas as DAI com resposta boa a moderada. No entanto, as síndromes periódicas associadas à criopirina (CAPS) pareciam não responder aos glicocorticoides. AINE e metotrexato foram os principais medicamentos utilizados no tratamento da CNO. Conclusões: Diferenças de pacientes com DAI foram observadas na população latino-americana em pacientes agrupados por sexo e idade ao diagnóstico da doença.

Screening program for familial hyperchylomicronemia syndrome detection: Experience of a university health system

ABSTRACT Objective: Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive metabolic disorder caused by mutations related to chylomicron metabolism. The objective of this study is to show the development and results of a screening program for FCS in Argentina. Materials and methods: A cross-sectional study was performed. All patients > 18 years with a triglyceride level ≥ 1,000 mg/dL in the period from January 1, 2017 to December 31, 2021 were included. The program was developed in three stages: (1) Review of electronic records and identification of suspected laboratory cases (triglyceride level ≥ 1,000 mg/dL); (2) Identification of suspected clinical cases (all suspected laboratory cases that had no relevant secondary factors) and application of the FCS score to define probable cases (score ≥ 10); (3) Perform genetic tests in probable cases. Results: Globally, 348 suspected laboratory cases (mean age of 49.9 years, 77.3% men) were included. The median triglycerides level was 1,309 mg/dL (interquartile range 1,175-1,607 mg/dL). In total, 231 patients were categorized as suspected clinical cases. After applying the FCS score, 3% of them were classified as "very likely FCS" (probable cases). Four variants of uncertain significance have been identified. No previously reported pathogenic variants were detected. Conclusion: This study shows a screening program for the detection of FCS. Although no patient was diagnosed with FCS, we believe that more programs of these characteristics should be developed in our region, given the importance of early detection of this metabolic disorder.

Indirect costs associated with "free" paediatric haemodialysis: Experience from Karachi, Pakistan

Treatment of children with end-stage kidney disease (ESKD), requiring maintenance dialysis, poses unique challenges. In low- and middle-income countries, lifelong treatment leads to significant stress on the overall family unit. Families face serious financial, social and psychological consequences despite free treatment. This pilot study, utilising primarily quantitative methods, supplemented by two case studies, is set in Sindh Institute of Urology and Transplantation, a tertiary care hospital in Karachi, Pakistan, providing free medical treatment. Fifty-two caretakers of children receiving haemodialysis for more than five years participated in the quantitative arm. Findings reveal that additional financial challenges may send the entire household into financial catastrophe. Social problems include migration from native cities, impact on the education of the sick child along with changes in lives of siblings. One-third of primary caretakers screened positive for anxiety/depression. Healthcare professionals 'practising' in developing countries face considerable ethical dilemmas in their practice when offering “free” paediatric dialysis services knowing the financial and psychological burden imposed on families.

Brazilian consensus for diagnosis, management and treatment of hereditary transthyretin amyloidosis with peripheral neuropathy: second edition / Consenso brasileiro para o diagnóstico, manejo e tratamento da polineuropatia amiloidótica familiar associada à transtirretina: segunda edição

Abstract Hereditary transthyretin amyloidosis with peripheral neuropathy (ATTRv-PN) is an autosomal dominant inherited sensorimotor and autonomic polyneuropathy with over 130 pathogenic variants identified in the TTR gene. Hereditary transthyretin amyloidosis with peripheral neuropathy is a disabling, progressive and life-threatening genetic condition that leads to death in ~ 10 years if untreated. The prospects for ATTRv-PN have changed in the last decades, as it has become a treatable neuropathy. In addition to liver transplantation, initiated in 1990, there are now at least 3 drugs approved in many countries, including Brazil, and many more are being developed. The first Brazilian consensus on ATTRv-PN was held in the city of Fortaleza, Brazil, in June 2017. Given the new advances in the area over the last 5 years, the Peripheral Neuropathy Scientific Department of the Brazilian Academy of Neurology organized a second edition of the consensus. Each panelist was responsible for reviewing the literature and updating a section of the previous paper. Thereafter, the 18 panelists got together virtually after careful review of the draft, discussed each section of the text, and reached a consensus for the final version of the manuscript.

Resumo Polineuropatia amiloidótica familiar associada a transtirretina (ATTRv-PN) é uma polineuropatia sensitivo-motora e autonômica hereditária autossômica dominante com mais de 130 variantes patogênicas já identificadas no gene TTR. A ATTRv-PN é uma condição genética debilitante, progressiva e que ameaça a vida, levando à morte em ~ 10 anos se não for tratada. Nas últimas décadas, a ATTRv-PN se tornou uma neuropatia tratável. Além do transplante de fígado, iniciado em 1990, temos agora 3 medicamentos modificadores de doença aprovados em muitos países, incluindo o Brasil, e muitas outras medicações estão em desenvolvimento. O primeiro consenso brasileiro em ATTRv-PN foi realizado em Fortaleza em junho de 2017. Devido aos novos avanços nesta área nos últimos 5 anos, o Departamento Científico de Neuropatias Periféricas da Academia Brasileira de Neurologia organizou uma segunda edição do consenso. Cada panelista ficou responsável por rever a literatura e atualizar uma parte do manuscrito. Finalmente, os 18 panelistas se reuniram virtualmente após revisão da primeira versão, discutiram cada parte do artigo e chegaram a um consenso sobre a versão final do manuscrito.

Very low HDL levels: clinical assessment and management

ABSTRACT In individuals with very low high-density lipoprotein (HDL-C) cholesterol, such as Tangier disease, LCAT deficiency, and familial hypoalphalipoproteinemia, there is an increased risk of premature atherosclerosis. However, analyzes based on comparisons of populations with small variations in HDL-C mediated by polygenic alterations do not confirm these findings, suggesting that there is an indirect association or heterogeneity in the pathophysiological mechanisms related to the reduction of HDL-C. Trials that evaluated some of the HDL functions demonstrate a more robust degree of association between the HDL system and atherosclerotic risk, but as they were not designed to modify lipoprotein functionality, there is insufficient data to establish a causal relationship. We currently have randomized clinical trials of therapies that increase HDL-C concentration by various mechanisms, and this HDL-C elevation has not independently demonstrated a reduction in the risk of cardiovascular events. Therefore, this evidence shows that (a) measuring HDL-C as a way of estimating HDL-related atheroprotective system function is insufficient and (b) we still do not know how to increase cardiovascular protection with therapies aimed at modifying HDL metabolism. This leads us to a greater effort to understand the mechanisms of molecular action and cellular interaction of HDL, completely abandoning the traditional view focused on the plasma concentration of HDL-C. In this review, we will detail this new understanding and the new horizon for using the HDL system to mitigate residual atherosclerotic risk.

A case of neonatal-onset type I hyperlipoproteinemia with bloody ascites / 中国当代儿科杂志

This report presents a case of a male infant, aged 32 days, who was admitted to the hospital due to 2 days of bloody stools and 1 day of fever. Upon admission, venous blood samples were collected, which appeared pink. Blood biochemistry tests revealed elevated levels of triglycerides and total cholesterol. The familial whole genome sequencing revealed a compound heterozygous variation in the LPL gene, with one variation inherited from the father and the other from the mother. The patient was diagnosed with lipoprotein lipase deficiency-related hyperlipoproteinemia. Acute symptoms including bloody stools, fever, and bloody ascites led to the consideration of acute pancreatitis, and the treatment involved fasting, plasma exchange, and whole blood exchange. Following the definitive diagnosis based on the genetic results, the patient was given a low-fat diet and received treatment with fat-soluble vitamins and trace elements, as well as adjustments to the feeding plan. After a 4-week hospitalization, the patient's condition improved and he was discharged. Follow-up showed a decrease in triglycerides and total cholesterol levels. At the age of 1 year, the patient's growth and psychomotor development were normal. This article emphasizes the multidisciplinary diagnosis and treatment of familial hyperlipoproteinemia presenting with symptoms suggestive of acute pancreatitis, including bloody ascites, in the neonatal period.

Research progresses on pathogenic genes and related signal pathways of familial exudative vitreoretinopathy / 中华眼底病杂志

Familial exudative vitreoretinopathy (FEVR) is a serious hereditary retinal vascular disease. The clinical manifestations vary, and the severity of the patients' condition is different. In severe cases, it may lead to bilateral blindness. The pathogenic mechanism of FEVR is also complex. At present, more than ten classical and candidate pathogenic genes have been found: NDP, FZD4, LRP5, TSPAN12, CTNNB1, KIF11, ZNF408, RCBTB1, LRP6, CTNNA1, CTNND1, JAG1, ATOH7, DLG1, DOCK6, ARHGP31 and EVR3 region. These pathogenic genes are involved in Wnt/β-catenin signaling pathway, norrin/β-catenin pathway and Notch pathway. They regulate and affect the development of retinal blood vessels, hyaloid vascular system regression, endothelial cell connections, and blood retinal barrier homeostasis, ultimately leading to the occurrence and development of FEVR disease.

The macular structure and blood flow in familial exudative vitreoretinopathy with inner retinal layer persistence / 中华眼底病杂志

Objective:To compared the changes of macular microvascular architecture in early stage familial exudative vitreoretinopathy (FEVR) patients with inner retinal layer (IRL) persistence and without IRL persistence.Methods:A retrospective clinical study. From 2017 to 2022, 94 patients with stage 1 FEVR with or without IRL residue and 45 age- and sex-matched healthy volunteers with 45 eyes (normal control group) who were confirmed by ophthalmology examination in Hangzhou Hospital of Optometry Affiliated to Wenzhou Medical University and Zhejiang Provincial People's Hospital were included in the study. According to whether there was IRL residue, the patients were divided into IRL group and non-IRL group, with 22 patients (22 eyes) and 72 patients (72 eyes), respectively. Best corrected visual acuity (BCVA) and optical coherence tomography angiography (OCTA) were performed in all eyes. Superficial vessel density (SCP) and deep vessel density (DCP) of whole image, fovea and parafovea, the area and perimeter of fovea avascular area (FAZ), A-circularity index (AI, perimeter/standard circle perimeter with equal area) and vessel density around the 300 μm width of the FAZ (FD), central macular thickness (CMT) on macular 3 mm × 3 mm scan on OCTA were measured.Results:SCP and DCP of whole image ( F=10.774, 4.583) and parafovea ( F=10.433, 3.912), CMT ( F=171.940) in IRL group and non-IRL group on macular 3 mm × 3 mm scan on OCTA were significantly lower than that in normal persons ( P<0.05). There were significant differences among three groups of the area of FAZ ( F=4.315), AI ( F=3.413), FD-300 ( F=13.592) ( P<0.05). BCVA were worst in IRL group ( P<0.05). Conclusions:Blood flow density decreased in macular area of FEVR patients. CMT is significantly thicker than normal population. The FAZ area of the foveal IRL residual eyes is small and irregular, with worse BCVA and lower macular blood density.

Clinical features and treatment of glaucoma secondary to familial exudative vitreoretinopathy / 中华眼底病杂志

Objective:To investigate the etiology, clinical features and treatment of familial exudative vitreoretinopathy (FEVR) secondary glaucoma.Methods:A retrospective clinical study. From January 1, 2016 to January 1, 2022, 15 patients (17 eyes) were diagnosed with FEVR secondary glaucoma in Beijing Tongren Hospital, Capital Medical University were included in the study. All patients underwent systematic ophthalmological evaluation. According to the patient's age, visual acuity, intraocular pressure, anterior segment, vitreous body and retina condition, the choice of translimbal lensectomy combined with vitrectomy, goniectomy, cyclophotocoagulation, intravitreal injection of anti-vascular endothelial growth factor (VEGF) treatment were chosen. The follow-up time was 3 to 37 months. The clinical characteristics of the affected eye, and the changes of intraocular pressure, anterior chamber depth and complications after surgery were observed.Results:Among the 15 patients, there were 11 males with 13 eyes, and 4 females with 4 eyes. Age was 6.14±7.37 years old. FEVR stages 2B, 3B, 4A, 4B, 5A, and 5B were 1, 1, 5, 6, 3, and 1 eye, respectively. The intraocular pressure of the affected eye was 42.74±9.06 mm Hg (1 mm Hg=0.133 kPa). All eyes had shallow anterior chamber and angle closure, anterior or posterior iris adhesions, lens opacity, retinal detachment, iris neovascularization in 4 eyes, and vitreous hemorrhage in 2 eyes. Sixteen eyes were treated with translimbal lensectomy combined with vitrectomy and goniotomy, of which 8 eyes were treated with anti-VEGF treatment; 1 eye was treated with cyclophotocoagulation combined with anti-VEGF treatment. After operation, the intraocular pressure of 16 eyes returned to normal range, and the depth of anterior chamber of 16 eyes returned to normal, and no obvious complications occurred.Conclusions:The main etiology of secondary glaucoma in FEVR is the structural and functional abnormalities of the anterior chamber and angle, which are found in the 2B and above stages of FEVR. The lensectomy and vitrectomy via limbal approach can effectively control the intraocular pressure and restore the anterior chamber, with no serious complications.

Analysis of factors affecting the clinical features of familial exudative vitreoretinopathy / 中华眼底病杂志

Objective:To observe and investigate the related factors that might affect clinical features of familial exudative vitreoretinopaty (FEVR) patients.Methods:A retrospective chart study. From January 2012 and December 2021, 42 patients with 84 eyes with a diagnosis of FEVR from Department of Ophthalmology, Peking University People's Hospital were included in the study. The patients came from 42 separate families. There were 31 males and 11 females, with an average age of first diagnosis was 16.6±33.7 months. There were 21 patients referred from other hospitals for the fundus disease found in eye screening after birth, 21 patients were first seen in our hospital. There were 4 and 38 premature and full-term infants, respectively. Two patients with a positive family history of FEVR. All patients are FEVR stages 1-5. The wide-angle digital pediatric retinal imaging system after general anesthesia for fluorescein fundus angiography (FFA) examination were performed for patients aged <5 years. If patients ≥ 5 years old, routine FFA examination was performed. Sixty-eight first-degree relatives from 28 families undergo routine fundus examinations and FFA examination. Genetic examination was performed for 26 families, including 26 probands and 57 first-degree relatives. Genetic examination were performed on gene the coreceptor of low density lipoprotein receptor-associated protein 5 ( LRP5), Wnt receptor coiled protein 4 ( FZD4), Norrie disease ( NDP), tetraporin 12 ( TSPAN12), catenin β1 ( CTNNB1) genes known to be involved in FEVR. The clinical features and the genotype of FEVR were observed in relation to the clinical phenotype. Results:Among the 42 patients, 13 patients were first observed by strabismus and nystagmus, with the median age of 12 months. Eight patients were complained non-chasing or vision-related symptoms. Among the 84 eyes, FEVR stage 1 or 2, 3 or 4, and 5 were 50 (59.5%, 50/84), 31 (36.9%, 31/84), and 3 (3.6%, 3/84) eyes, respectively. Among the 23 patients who were > 3 months at first diagnosis, 16 patients had at least one eye severer than stage 3 (69.6%, 16/23). Of the 68 first-degree relatives, 22 (32.4%, 22/68) had FEVR-like changes. Among the 26 families that underwent genetic detection, 13 families (50%, 13/26) of 16 variants of FEVR-related genes were detected, of which 10 mutations of LRP5 gene were the most common. There were 10 families with single gene mutations, including 6, 2 and 2 families of LRP5, FZD4 and CTNNB1 genes, respectively. One family of LRP5 gene mutations were compound heterozygous mutations, 1 family with LRP5 gene mutaition combined with NDP gene mutation, and 1 family with LRP5 and TSPAN12 gene mutation. Among the proband with FEVR pathogenic genes, 6 cases with similiar stage of both eyes, and 7 cases with inconsistent disease stages, and there was no obvious correlation between gene mutations and clinical phenotypes. Conclusion:In addition to the age of first diagnosis, no exact factors affecting the clinical manifestations of FEVR are found, and the association between clinical phenotypic and genetic heterogeneity still needs to be further explored.

Clinical, genetic characteristics and follow-up in 14 patients with transthyretin familial amyloid polyneuropathy / 中华神经科杂志

Objective:To summarize the clinical and genetic characteristics in patients with transthyretin familial amyloid polyneuropathy (TTR-FAP).Methods:Fourteen unrelated TTR-FAP patients diagnosed at Xuanwu Hospital, Capital Medical University from September 2014 to February 2022 were retrospectively reviewed. The clinical manifestation, electrophysiology, cardiac function, biopsy and gene mutation were analyzed.Results:In the 14 patients (13 males, 1 female) diagnosed as TTR-FAP, the mean age at onset was 53.9 years (range: 33.0-71.0 years), with a mean course from symptom-onset to diagnosis of 4.1 years. The late-onset type occurred in 9 cases. Seven patients had a family history of TTR-FAP. Distal paresthesia of lower limbs was the commonest initial symptom (8 cases), with sensorimotor neuropathy and autonomic dysfunction seen initially in 4 and 2 cases, respectively. Cardiac involvement occurred in 6/8 of the patients. Nerve conduction studies indicated extremely axonal impairment with demyelinating features. Sural nerve biopsies showed moderate to severe axonal loss of myelinated fibers and the positive rate of Congo red staining was 8/14. Of 8 different TTR mutations detected, V50M was the most common (appearing in 5 cases). No obvious neuropathy progression was seen in the 5 patients who received tafamidis and 2 patients died of dyscrasia. Conclusions:TTR-FAP is more common in males, with sensorimotor axonal polyneuropathy, autonomic dysfunction and cardiac subclinical damage as the predominant symptoms. V50M is the commonest mutation. Tafamidis can delay the progression of disability.

Clinical research advances of liver transplantation for patients with familial hypercholesterolemia / 中华器官移植杂志

Familial hypercholesterolemia(FH)is an autosomal dominant disease.Homozygous FH patients tend to have a high incidence of severe arteriosclerotic cardiovascular disease during adolescence and die at ages of 20-30.Liver transplantation(LT)may correct the dysfunction of LDL receptor on hepatocytes, restore normal lipoprotein metabolism, arrest disease progression and improving patient outcomes.However, due to a great rarity of LT for FH, domestic transplantation centers lack the relevant clinical experiences.This review summarized some important issues of FH patients undergoing LT, such as indications, timing, donor sources, efficacies, complications and reusing diseased liver.The goal was to provide practical references for managing FH.

ADAM10 gene mutations caused familial progressive hyperpigmentation / 中华皮肤科杂志

Objective:To identify the causative gene in patients with familial progressive hyperpigmentation (FPH) .Methods:Two families with FPH were collected in March 2005 and March 2015 respectively, and their phenotypes were observed and recorded. The causative gene was investigated by single nucleotide polymorphism (SNP) -based genome-wide linkage analysis and exome sequencing, and verified by Sanger sequencing. The candidate gene expression was determined in FPH lesions and normal skin tissues by using immunohistochemical techniques.Results:The genome-wide linkage analysis showed that the causative gene in FPH family 1 was mapped to the loci of rs1026369-rs11857925 on chromosome 15q21.1 - q22.2; a disintegrin and metalloproteinase 10 (ADAM10) gene was identified as the possible causative gene by exome sequencing; Sanger sequencing showed that a splice-site mutation c.1511+1G>A in the ADAM10 gene was co-segregated with the disease phenotype in the FPH family 1. Immunohistochemical staining demonstrated that ADAM10 was expressed in both the FPH lesions and normal skin tissues of the proband in the FPH family 1. A missense mutation c.1172C>T (p.Ser319Phe) was identified by further ADAM10 mutation analysis in another 3-generation family with FPH (family 2). Both the above mutations were not detected in 300 local healthy controls.Conclusion:ADAM10 was identified as a novel causative gene responsible for FPH.

Detection of ATP2C1 gene mutations in a family with generalized familial benign chronic pemphigus / 中华皮肤科杂志

A 60-year-old female proband presented with recurrent erythema, blisters and erosions all over the body for 30 years, which had been aggravated 10 days prior to the presentation. Skin examination showed erythematous swelling of the bilateral eyelids with scattered dark red crusts, scattered erythema and erosions on the nasolabial folds and chin, large areas of erythema and erosions on the neck, bilateral axillae, left cubital fossa, perineum and perianal area, accompanied by bright red granulation tissues and positive Nikolsky′s sign. The proband had two sons, both of whom occasionally presented with erythema and erosions on the axillae and groin, and had not been diagnosed or treated. Blood samples were collected from the proband and her two sons, and genomic DNA was extracted and subjected to whole-exome sequencing. A heterozygous deletion mutation c.955_957del (p.A319del) was identified in the ATP2C1 gene in the proband and her two sons, which had not been previously reported. The patient was finally diagnosed with generalized familial benign chronic pemphigus.

Mechanisms of PiT2-loop7 Missense Mutations Induced Pi Dyshomeostasis / 神经科学通报·英文版

PiT2 is an inorganic phosphate (Pi) transporter whose mutations are linked to primary familial brain calcification (PFBC). PiT2 mainly consists of two ProDom (PD) domains and a large intracellular loop region (loop7). The PD domains are crucial for the Pi transport, but the role of PiT2-loop7 remains unclear. In PFBC patients, mutations in PiT2-loop7 are mainly nonsense or frameshift mutations that probably cause PFBC due to C-PD1131 deletion. To date, six missense mutations have been identified in PiT2-loop7; however, the mechanisms by which these mutations cause PFBC are poorly understood. Here, we found that the p.T390A and p.S434W mutations in PiT2-loop7 decreased the Pi transport activity and cell surface levels of PiT2. Furthermore, we showed that these two mutations attenuated its membrane localization by affecting adenosine monophosphate-activated protein kinase (AMPK)- or protein kinase B (AKT)-mediated PiT2 phosphorylation. In contrast, the p.S121C and p.S601W mutations in the PD domains did not affect PiT2 phosphorylation but rather impaired its substrate-binding abilities. These results suggested that missense mutations in PiT2-loop7 can cause Pi dyshomeostasis by affecting the phosphorylation-regulated cell-surface localization of PiT2. This study helps understand the pathogenesis of PFBC caused by PiT2-loop7 missense mutations and indicates that increasing the phosphorylation levels of PiT2-loop7 could be a promising strategy for developing PFBC therapies.

Advances in diagnosis and treatment of familial hypercholesterolemia / 南方医科大学学报

Familial hypercholesterolemia (FH) is an autosomal dominant inherited disease caused by abnormal lipoprotein metabolism. Patients with FH have a significantly increased risk of coronary artery disease (CAD) due to long-term exposure to high levels of low-density lipoprotein (LDL). The diagnosis of FH relies heavily on gene detection, and examination of LDL receptor (LDLR) function is of great significance in its treatment. This review summarizes the current advances in the screening, diagnosis, and treatment of FH and functional analysis of LDLR gene mutations.

Analysis of family mutation type and two-hit hypothesis of a familial VHL Syndrome patient / 现代泌尿外科杂志

【Objective】 To explore the mutation type, clinical characteristics, molecular genetics and the two-hit type of a patient with familial Von Hippel Lindau (VHL) syndrome. 【Methods】 The data of the patient were collected. DNA was extracted from the peripheral blood and renal cell carcinoma sample. The VHL gene germline mutation site was detected with high throughput sequencing next generation sequencing (NGS). The two-hit site was identified with UCSCXena database, methylation-specific PCR (MSP) and microsatellite stability detection. 【Results】 The mutation site of the embryo line was located in c.500G>A R167Q mutation. The patient had single nucleotide polymorphism, but no clear loss of heterozygosity, methylation or system mutation. 【Conclusion】 The germline mutation in exon 3 is the basis for the clinical features of this familial renal cell carcinoma proband. The identification of the two-hit site is key to the occurrence of the disease, which is significant for the diagnosis and treatment. The use of the databases can guide the screening of mutations and methylation sites in familial renal cell carcinoma.

An Early Onset of Myocardial Infarction Patient with Syphilis and Familial Hypercholesterolemia / 罕见病研究

Syphilis may affect the cardiovascular system, in which coronary arteries are less commonly involved. Familial hypercholesterolemia (FH) is an autosomal dominant inherited disease with elevated low-density lipoprotein-cholesterol (LDL-C) levels due to impaired LDL-C clearance. We report a young male patient with syphilis and FH. The clinical manifestations were acute myocardial infarction and high LDL-C levels. Coronary angiography and intracoronary imaging showed multiple aneurysmal ectasia and stenosis. A drug-eluting stent was implemented when recurrent restenosis occurred after two percutaneous coronary drug-eluting balloon angioplasties.

Familial Hypercholesterolemia / 罕见病研究

Familial hypercholesterolemia (FH) is a group of autosomal co-dominant genetic diseases mainly characterized by abnormal low-density lipoprotein related metabolism. It is one of the most common inherited diseases in children and one of the most serious lipid metabolism diseases which results in various life-threatening cardiovascular diseases and the complications. In recent years, the treatment protocols for FH have diversified thanks to the deeper understanding of the disease in China and abroad and the development of new lipid-lowering drugs. However, the current awareness and diagnosis rate of FH are very low. The treatment of the disease is much inadequate. This paper summarizes the clinical characteristics, diagnosis, screening strategy, and treatment of FH hoping to enhance the understanding and awareness of the disease in the society.