Identify truly high-risk TP53-mutated diffuse large B cell lymphoma patients and explore the underlying biological mechanisms.

TP53 mutation (TP53-mut) correlates with inferior survival in many cancers, whereas its prognostic role in diffuse large B-cell lymphoma (DLBCL) is still in controversy. Therefore, more precise risk stratification needs to be further explored for TP53-mut DLBCL patients. A set of 2637 DLBCL cases from multiple cohorts, was enrolled in our analysis. Among the 2637 DLBCL patients, 14.0% patients (370/2637) had TP53-mut. Since missense mutations account for the vast majority of TP53-mut DLBCL patients, and most non-missense mutations affect the function of the P53 protein, leading to worse survival rates, we distinguished patients with missense mutations. A TP53 missense mutation risk model was constructed based on a 150-combination machine learning computational framework, demonstrating excellent performance in predicting prognosis. Further analysis revealed that patients with high-risk missense mutations are significantly associated with early progression and exhibit dysregulation of multiple immune and metabolic pathways at the transcriptional level. Additionally, the high-risk group showed an absolutely suppressed immune microenvironment. To stratify the entire cohort of TP53-mut DLBCL, we combined clinical characteristics and ultimately constructed the TP53 Prognostic Index (TP53PI) model. In summary, we identified the truly high-risk TP53-mut DLBCL patients and explained this difference at the mutation and transcriptional levels.

Genetic evidence for predisposition to acute leukemias due to a missense mutation (p.Ser518Arg) in ZAP70 kinase: a case-control study.

BACKGROUND: The apparent lack of additional missense mutations data on mixed-phenotype leukemia is noteworthy. Single amino acid substitution by these non-synonymous single nucleotide variations can be related to many pathological conditions and may influence susceptibility to disease. This case-control study aimed to unravel whether the ZAP70 missense variant (rs104893674 (C > A)) underpinning mixed-phenotype leukemia. METHODS: The rs104893674 was genotyped in clients who were mixed-phenotype acute leukemia-, acute lymphoblastic leukemia- and acute myeloid leukemia-positive and matched healthy controls, which have been referred to all major urban hospitals from multiple provinces of country- wide, IRAN, from February 11' 2019 to June 10' 2023, by amplification refractory mutation system-polymerase chain reaction method. Direct sequencing for rs104893674 of the ZAP70 gene was performed in a 3130 Genetic Analyzer. RESULTS: We found that the AC genotype of individuals with A allele at this polymorphic site (heterozygous variant-type) contribute to the genetic susceptibility to acute leukemia of both forms, acute myeloid leukemia and acute lymphoblastic leukemia as well as with a mixed phenotype. In other words, the ZAP70 missense variant (rs104893674 (C > A)) increases susceptibility of distinct cell populations of different (myeloid and lymphoid) lineages to exhibiting cancer phenotype. The results were all consistent with genotype data obtained using a direct DNA sequencing technique. CONCLUSION: Of special interest are pathogenic missense mutations, since they generate variants that cause specific molecular phenotypes through protein destabilization. Overall, we discovered that the rs104893674 (C > A) variant chance in causing mixed-phenotype leukemia is relatively high.

Clinical and structural insights into the rare but oncogenic HER2-activating missense mutations in non-small cell lung cancer: a retrospective ATLAS cohort study.

BACKGROUND: Unlike human epidermal growth factor receptor 2 (HER2) amplification or exon 20 insertions, missense mutations in the extracellular domain (ECD), transmembrane domain (TMD), and intracellular domain (ICD) of the HER2 protein have been implicated as oncogenic in non-small cell lung cancer (NSCLC). However, their molecular subtypes, structural disparities, and clinical responses to current medical treatments, particularly HER2-targeted tyrosine kinase inhibitors (TKIs), remain unclear in NSCLC and warrant investigation. METHODS: A real-world observational ATLAS study was conducted to gather and analyze therapeutic outcomes of chemotherapy or TKIs for heterogeneous HER2 missense mutations in NSCLC. Computational models of typical ECD, TMD, and ICD mutations were utilized to explore their structural variances. RESULTS: We screened 37 eligible patients with HER2-activating missense mutations, of which 35 patients who had received chemotherapy or HER2-targeted TKIs as first-line therapy were available for response assessment. The median progression-free survival (PFS) for chemotherapy was 4.43 months (95% confidence interval [CI], 3.77-5.10), with an objective response rate (ORR) of 26.1% (6/23) and a disease control rate (DCR) of 17/23 (73.9%). The administration of afatinib, dacomitinib, and pyrotinib, HER2-targeted TKIs, achieved a median PFS of 4.65 months, with an ORR of 33.3% (4/12) and a DCR of 83.3% (10/12). Molecular modeling and computational simulations of ECD, TMD, and ICD mutations revealed their distinct structural characteristics. CONCLUSION: In comparison to chemotherapy, HER2-targeted TKIs demonstrated similar activity and PFS benefits for HER2-activating missense mutations in NSCLC.

Analysis of mutational variations in TP53 tumour suppressor gene among Pakistani head and neck cancer patients.

The aim of this study was to determine the frequency of TP53 mutation among Pakistani head and neck cancer (HNC) patients who visited Nishtar Hospital Multan and Nishtar Institute of Dentistry (NID), Multan, Pakistan. While significant research has been conducted on the role of p53 in HNC throughout the world, this study is the first of its kind in Southern Punjab, Pakistan. A total of 242 samples (121 cases and 121 controls) were collected from Nishtar Hospital Multan and NID, Multan, Pakistan. After histopathological analysis to determine the stage type and grade of malignancy, DNA extraction and sequencing were carried out to assess any mutations in the TP53 region (exons 5-8). Genetic screening was performed by the polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) technique and Chromas 2.6.6 was used to visualise the sequencing results. The mean age of cases was 50.73 ±16.41 years and controls were 37.55 ± 15.51 years. The frequency of HNC was higher in male patients (65.28%) than in female patients (34.71%). Overall, this cancer was found to be significantly more prevalent in the age group of >35-55 years (p < 0.001). Smoking (51% versus 14%), naswar usage (15.7% versus 6.6%), poor oral hygiene (52.9% versus 29.8%) and anemic status (57.0% versus 4.1%) were significantly associated with cases (p ≤ 0.05) compared to controls. Only 04 samples exon 5 (1 sample), exon 7 (2 samples) and exon 8 (1 sample) with changed mobility patterns were found on the SSCP gel. All mutations were missense and heterozygous. Out of four mutant samples, three mutations were in the hotspot regions (codon 175, 245 and 248) of p53. Based on this study, there may be a weak association between the TP53 exon 5-8 mutation and HNC patients in Southern Punjab, Pakistan.

A random mutagenesis screen enriched for missense mutations in bacterial effector proteins.

To remodel their hosts and escape immune defenses, many pathogens rely on large arsenals of proteins (effectors) that are delivered to the host cell using dedicated translocation machinery. Effectors hold significant insight into the biology of both the pathogens that encode them and the host pathways that they manipulate. One of the most powerful systems biology tools for studying effectors is the model organism, Saccharomyces cerevisiae. For many pathogens, the heterologous expression of effectors in yeast is growth inhibitory at a frequency much higher than housekeeping genes, an observation ascribed to targeting conserved eukaryotic proteins. Abrogation of yeast growth inhibition has been used to identify bacterial suppressors of effector activity, host targets, and functional residues and domains within effector proteins. We present here a yeast-based method for enriching for informative, in-frame, missense mutations in a pool of random effector mutants. We benchmark this approach against three effectors from Legionella pneumophila, an intracellular bacterial pathogen that injects a staggering >330 effectors into the host cell. For each protein, we show how in silico protein modeling (AlphaFold2) and missense-directed mutagenesis can be combined to reveal important structural features within effectors. We identify known active site residues within the metalloprotease RavK, the putative active site in SdbB, and previously unidentified functional motifs within the C-terminal domain of SdbA. We show that this domain has structural similarity with glycosyltransferases and exhibits in vitro activity consistent with this predicted function.

A novel AVPR2 gene mutation in a Chinese pedigree with nephrogenic diabetes insipidus.

Nephrogenic diabetes insipidus (NDI) is a rare genetic disorder primarily associated with mutations in the arginine vasopressin receptor 2 (AVPR2) gene or the aquaporin 2 (AQP2) gene, resulting in impaired water reabsorption in the renal tubules. This report describes a case of a young male patient with NDI from China with a history of polydipsia and polyuria for over 15 years. Laboratory examinations of the proband indicated low urine-specific gravity and osmolality. Urologic ultrasound revealed severe bilateral hydronephrosis in both kidneys, bilateral dilatation of the ureters, roughness of the bladder wall, and the formation of muscle trabeculae. The diagnosis of diabetes insipidus was confirmed by water deprivation tests. The administration of posterior pituitary hormone did not alter urine-specific gravity, and osmolality remained at a low level (<300 mOsm/kg). Based on these findings, and the genetic tests of the proband and his parents were performed. A missense mutation (c.616 G>C) in exon 3 of the AVPR2 gene of the proband was found, caused by the substitution of amino acid valine to leucine at position 206 [p.Val206Leu], which was a hemizygous mutation and consistent with X-chromosome recessive inheritance. The administration of oral hydrochlorothiazide improves the symptoms of polydipsia and polyuria in the proband. This novel AVPR2 gene mutation may be the main cause of NDI in this family, which induces a functional defect in AVPR2, and leads to reduced tubular reabsorption of water.

An integrated multitool analysis contributes elements to interpreting unclassified factor IX missense variants associated with hemophilia B.

BACKGROUND: Dissection of genotype-phenotype relationships in hemophilia B (HB) is particularly relevant for challenging (mild HB) or for HB-associated but unclassified factor (F)IX missense variants. OBJECTIVE: To contribute elements to interpret unclassified HB-associated FIX missense variants by a multiple-level approach upon identification of a reported, but uncharacterized, FIX missense variant associated with mild HB. METHODS: Molecular modeling of wild-type and V92A FIX variants, expression studies in HEK293 cells with evaluation of protein (ELISA, western blotting) and activity (activated partial thromboplastin time-based/chromogenic assays) levels after recombinant expression, and multiple prediction tools. RESULTS: The F9(NM_000133.4):c.275T>C (p.V92A) variant was found in a mild HB patient (antigen, 45.4 U/dL; coagulant activity, 23.6 IU/dL; specific activity, 0.52). Newly generated molecular models showed alterations in Gla/EGF1-EGF2 domain conformation impacting Ca++ affinity and protein-protein interactions with activated factor XI (FXIa). Multitool analysis indicated a moderate impact on protein structure/function of the valine-to-alanine substitution, in accordance with patient and modeling data. Expression studies on the V92A variant showed a specific activity (0.49 ± 0.07; wild-type, 1.0 ± 0.1) recapitulating that of the natural variant, and pointed toward a moderate activation impairment as the main determinant underlying the p.V92A defect. The validated multitool approach, integrated with evidence-based data, was challenged on a panel (n = 9) of unclassified FIX missense variants, which resulted in inferred protein (secretion/function) outputs and HB severity. CONCLUSION: The rational integration of multitool and multiparameter analyses contributed elements to interpret genotype/phenotype relationships of unclassified FIX missense variants, with implications for diagnosis, management, and treatment of HB patients, and potentially translatable into other human disorders.

Compound heterozygous variants in SLC45A1 might cause syndromic intellectual disability by localization failure and activity attenuation in cells.

Intellectual disability (ID) is a kind of nervous developmental disorder and affects more than 1% of people worldwide. SLC45A1 as a transmembrane protein is implicated in the regulation of glucose homoeostasis. Through trio-based exome sequencing, the missense mutations of SLC45A1 c.103G>A (p.V35M) and c.1211T>G (p.F404C) were identified in the proband with syndromic ID. The distribution, expression and activity of SLC45A1 wild-type (WT) and variants were assayed in transfected COS7 cells. In SLC45A1 variants, the hydrogen bonds surrounding the 35th and 404th amino acid were changed, location on the cytomembrane was failed, their activity to transport glucose was also significantly decreased to contrast with SLC45A1-WT. No difference was observed at the mRNA and protein level. In conclusion, the compound heterozygous variants of SLC45A1 might be the genetic etiology for syndromic ID. These novel mutations probably attenuated its activity to transport glucose by the alteration of tertiary structure and failure of intracellular location.

MTR3D-AF2: Expanding the coverage of spatially derived missense tolerance scores across the human proteome using AlphaFold2.

The missense tolerance ratio (MTR) was developed as a novel approach to assess the deleteriousness of variants. Its three-dimensional successor, MTR3D, was demonstrated powerful at discriminating pathogenic from benign variants. However, its reliance on experimental structures and homologs limited its coverage of the proteome. We have now utilized AlphaFold2 models to develop MTR3D-AF2, which covers 89.31% of proteins and 85.39% of residues across the human proteome. This work has improved MTR3D's ability to distinguish clinically established pathogenic from benign variants. MTR3D-AF2 is freely available as an interactive web server at https://biosig.lab.uq.edu.au/mtr3daf2/.

Unravelling benzazepines and aminopyrimidine as multi-target therapeutic repurposing drugs for EGFR V774M mutation in neuroglioma patients.

Introduction: Neuroglioma, a classification encompassing tumors arising from glial cells, exhibits variable aggressiveness and depends on tumor grade and stage. Unraveling the EGFR gene alterations, including amplifications (unaltered), deletions, and missense mutations (altered), is emerging in glioma. However, the precise understanding of emerging EGFR mutations and their role in neuroglioma remains limited. This study aims to identify specific EGFR mutations prevalent in neuroglioma patients and investigate their potential as therapeutic targets using FDA-approved drugs for repurposing approach. Methods: Neuroglioma patient's data were analyzed to identify the various mutations and survival rates. High throughput virtual screening (HTVS) of FDA-approved (1615) drugs using molecular docking and simulation was executed to determine the potential hits. Results: Neuroglioma patient samples (n=4251) analysis reveals 19% EGFR alterations with most missense mutations at V774M in exon 19. The Kaplan-Meier plots show that the overall survival rate was higher in the unaltered group than in the altered group. Docking studies resulted the best hits based on each target's higher docking score, minimum free energy (MMGBSA), minimum kd, ki, and IC50 values. MD simulations and their trajectories show that compounds ZINC000011679756 target unaltered EGFR and ZINC000003978005 targets altered EGFR, whereas ZINC000012503187 (Conivaptan, Benzazepine) and ZINC000068153186 (Dabrafenib, aminopyrimidine) target both the EGFRs. The shortlisted compounds demonstrate favorable residual interactions with their respective targets, forming highly stable complexes. Moreover, these shortlisted compounds have drug- like properties as assessed by ADMET profiling. Conclusion: Therefore, compounds (ZINC000012503187 and ZINC000068153186) can effectively target both the unaltered/altered EGFRs as multi-target therapeutic repurposing drugs towards neuroglioma.

Requirement of ß subunit for the reduced voltage-gated Na+ current of a Brugada syndrome patient having novel double missense mutation (p.A385T/R504T) of SCN5A.

Mutations within the SCN5A gene, which encodes the α-subunit 5 (NaV1.5) of the voltage-gated Na+ channel, have been linked to three distinct cardiac arrhythmia disorders: long QT syndrome type 3, Brugada syndrome (BrS), and cardiac conduction disorder. In this study, we have identified novel missense mutations (p.A385T/R504T) within SCN5A in a patient exhibiting overlap arrhythmia phenotypes. This study aims to elucidate the functional consequences of SCN5A mutants (p.A385T/R504T) to understand the clinical phenotypes. Whole-cell patch-clamp technique was used to analyze the NaV1.5 current (INa) in HEK293 cells transfected with the wild-type and mutant SCN5A with or without SCN1B co-expression. The amplitude of INa was not altered in mutant SCN5A (p.A385T/R504T) alone. Furthermore, a rightward shift of the voltage-dependent inactivation and faster recovery from inactivation was observed, suggesting a gain-of-function state. Intriguingly, the coexpression of SCN1B with p.A385T/R504T revealed significant reduction of INa and slower recovery from inactivation, consistent with the loss-of-function in Na+ channels. The SCN1B dependent reduction of INa was also observed in a single mutation p.R504T, but p.A385T co-expressed with SCN1B showed no reduction. In contrast, the slower recovery from inactivation with SCN1B was observed in A385T while not in R504T. The expression of SCN1B is indispensable for the electrophysiological phenotype of BrS with the novel double mutations; p.A385T and p.R504T contributed to the slower recovery from inactivation and reduced current density of NaV1.5, respectively.

Missense and Non-Missense Lamin A/C Gene Mutations Are Similarly Associated with Major Arrhythmic Cardiac Events: A 20-Year Single-Centre Experience.

Arrhythmic risk stratification in patients with Lamin A/C gene (LMNA)-related cardiomyopathy influences clinical decisions. An implantable cardioverter defibrillator (ICD) should be considered in patients with an estimated 5-year risk of malignant ventricular arrhythmia (MVA) of ≥10%. The risk prediction score for MVA includes non-missense LMNA mutations, despite their role as an established risk factor for sudden cardiac death (SCD) has been questioned in several studies. The purpose of this study is to investigate cardiac features and find gene-phenotype correlations that would contribute to the evidence on the prognostic implications of non-missense vs. missense mutations in a cohort of LMNA mutant patients. An observational, prospective study was conducted in which 54 patients positive for a Lamin A/C mutation were enrolled, and 20 probands (37%) were included. The median age at first clinical manifestation was 41 (IQR 19) years. The median follow-up was 8 years (IQR 8). The type of LMNA gene mutation was distributed as follows: missense in 26 patients (48%), non-frameshift insertions in 16 (30%), frameshift deletions in 5 (9%), and nonsense in 7 (13%). Among the missense mutation carriers, two (8%) died and four (15%) were admitted onto the heart transplant list or underwent transplantation, with a major adverse cardiovascular event (MACE) rate of 35%. No statistically significant differences in MACE prevalence were identified according to the missense and non-missense mutation groups (p value = 0.847). Our data shift the spotlight on this considerable topic and could suggest that some missense mutations may deserve attention regarding SCD risk stratification in real-world clinical settings.

[Pedigree Analysis of Hereditary Coagulation Factor XII Deficiency Caused by Compound Heterozygous Mutation p.Gly175Cys and p.Gly542Ser of F12 Gene].

OBJECTIVE: To analyze the clinical phenotype and gene mutation of a genetic coagulation factor XII (FXII) deficiency pedigree and explore the molecular pathogenesis. METHODS: The activated partial thromboplastin time (APTT) and FXII activity (FXII:C) were detected by clotting method. The FXII antigen (FXII:Ag) was tested with ELISA. All exons and flanks of F12 gene were determined by Sanger sequencing. ClustalX-2.1-win, PROVEAN and Swiss-Pdb Viewer software were used to analyze the conservatism of amino acids at the mutant site, forecast whether the mutant amino acids were harmful and confirm the influence of the mutation on protein structure. RESULTS: The APTT of the proband prolonged to 71.3 s. The FXII:C and FXII:Ag were decreased to 5% and 6%, respectively. There were two heterozygous missense mutations c.580G>T and c.1681G>A detected in exon 7 and exon 14 of F12 gene, resulting in p.Gly175Cys and p.Gly542Ser, severally. Proband's father carried the p.Gly175Cys heterozygous mutation, while mother, brother and daughter had the p.Gly542Ser heterozygous mutation. Software analysis showed that both Gly175 and Gly542 were conserved, the two mutations were harmful and when mutations had occurred, the corresponding sites affected the protein local structure. CONCLUSION: The p.Gly175Cys and p.Gly542Ser compound heterozygous mutations are the molecular pathogenesis of the hereditary coagulation FXII deficiency pedigree. The p.Gly175Cys mutation has been detected for the first time in the world.

Exploring the link between Alport syndrome and multiple intracranial artery stenoses: a case report of COL4A5 mutation (118/120 characters).

BACKGROUND: Alport syndrome is a genetic disorder caused by mutations in the COL4A5 gene, which encodes type IV collagen α5 chain, leading to chronic nephritis, hearing loss, and ocular abnormalities. Recent reports suggest this genetic mutation may also increase the risk of cerebral aneurysms and fibromuscular dysplasia, indicating a potential association with vascular vulnerability. CASE PRESENTATION: A 66-year-old woman was admitted with recurrent transient weakness of the left hand, which had gradually worsened in duration over three months. Her medical history included chronic nephritis since childhood. Her two sons had end-stage renal disease and hearing loss since their 20s, and her mother also had chronic kidney disease and hearing loss. One son had a history of traumatic subarachnoid hemorrhage, and the other had spinal epidural hematoma. On admission, she had reduced renal function with proteinuria, acute cerebral infarction in the subcortical white matter of the right fronto-parietal and parieto-occipital lobes, and multiple intracranial arterial stenoses (ICAS), including the right middle and right posterior cerebral artery. Vessel wall imaging of the right middle cerebral artery showed a concentric stenotic pattern. Genetic tests identified a pathogenic missense mutation in exon 24 of COL4A5 (exon 24:c.G1700 >C: p.(Gly567Arg)) that was heterozygous for the patient and hemizygous for her son. She was diagnosed with Alport syndrome. CONCLUSION: It is important to consider Alport syndrome as a possible cause of ICAS in patients with a family history of renal failure or hearing loss and to conduct a genetic analysis of type IV collagen genes. (249/250 words).

SARS-CoV-2: Prediction of critical ionic amino acid mutations.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), that caused coronavirus disease 2019 (COVID-19), has been studied thoroughly, and several variants are revealed across the world with their corresponding mutations. Studies and vaccines development focus on the genetic mutations of the S protein due to its vital role in allowing the virus attach and fuse with the membrane of a host cell. In this perspective, we study the effects of all ionic amino acid mutations of the SARS-CoV-2 viral spike protein S1 when bound to Antibody CC12.1 within the SARS-CoV-2:CC12.1 complex model. Binding free energy calculations between SARS-CoV-2 and antibody CC12.1 are based on the Analysis of Electrostatic Similarities of Proteins (AESOP) framework, where the electrostatic potentials are calculated using Adaptive Poisson-Boltzmann Solver (APBS). The atomic radii and charges that feed into the APBS calculations are calculated using the PDB2PQR software. Our results are the first to propose in silico potential life-threatening mutations of SARS-CoV-2 beyond the present mutations found in the five common variants worldwide. We find each of the following mutations: K378A, R408A, K424A, R454A, R457A, K458A, and K462A, to play significant roles in the binding to Antibody CC12.1, since they are turned into strong inhibitors on both chains of the S1 protein, whereas the mutations D405A, D420A, and D427A, show to play important roles in this binding, as they are turned into mild inhibitors on both chains of the S1 protein.

Identification of a Homozygous Mutation of CCDC40 in a Chinese Infertile Man with MMAF and PCD-like Phenotypes.

Aims: Asthenozoospermia is the most common factor of male infertility, mainly caused by multiple morphological abnormalities of the sperm flagella (MMAF) and primary ciliary dyskinesia (PCD). Previous studies have shown that genetic factors may contribute to MMAF and PCD. The study aimed to identify novel potentially pathogenic gene mutations in a Chinese infertile man with MMAF and PCD-like phenotypes. Methods: A Chinese infertile man with MMAF and PCD was enrolled in this study. Whole exome sequencing and Sanger sequencing were performed to identify potential causative genes and mutations. Results: A novel homozygous missense mutation (c.1450G>A; p.E484K) of CCDC40 was finally identified and Sanger sequencing confirmed that the patient carried the homozygous mutation, which was inherited from his parents. We reported the first homozygous missense CCDC40 mutation in infertile men with MMAF but had other milder PCD symptoms. Conclusion: Our findings not only broaden the disease-causing mutation spectrum of CCDC40 but also provide new insight into the correlation between CCDC40 mutations and MMAF.

Novel MIP gene mutation causes autosomal-dominant congenital cataract.

AIM: To identify disease-causative mutations in families with congenital cataract. METHODS: Two Chinese families with autosomal-dominant congenital cataract (ADCC) were recruited and underwent comprehensive eye examinations. Gene panel next-generation sequencing of common pathogenic genes of congenital cataract was performed in the proband of each family. Sanger sequencing was used to valid the candidate gene mutations and sequence the other family members for co-segregation analysis. The effect of sequence changes on protein structure and function was predicted through bioinformatics analysis. Major intrinsic protein (MIP)-wildtype and MIP-G29R plasmids were constructed and microinjected into zebrafish single-cell stage embryos. Zebrafish embryonic lens phenotypes were screened using confocal microscopy. RESULTS: A novel heterozygous mutation (c.85G>A; p.G29R) in the MIP gene was identified in the proband of one family. A known heterozygous mutation (c.97C>T; p.R33C; rs864309693) in MIP was found in the proband of another family. In-silico prediction indicated that the novel mutation might affect the MIP protein function. Zebrafish embryonic lens was uniformly transparent in both wild-type PCS2+MIP and mutant PCS2+MIP. CONCLUSION: Two missense mutations in the MIP gene in Chinese cataract families are identified, and one of which is novel. These findings expand the genetic spectrum of MIP mutations associated with cataracts. The functional studies suggest that the novel MIP mutation might not be a gain-of-function but a loss-of-function mutation.

A rare missense PAX6 mutation causes atypical aniridia in a three-generation Chinese family.

AIM: To investigate the molecular diagnosis of a three-generation Chinese family affected with aniridia, and further to identify clinically a PAX6 missense mutation in members with atypical aniridia. METHODS: Eleven family members with and without atypical aniridia were recruited. All family members underwent comprehensive ophthalmic examinations. A combination of whole exome sequencing (WES) and direct Sanger sequencing were performed to uncover the causative mutation. RESULTS: Among the 11 family members, 8 were clinically diagnosed with congenital aniridia (atypical aniridia phenotype). A rare heterozygous mutation c.622C>T (p.Arg208Trp) in exon 8 of PAX6 was identified in all affected family members but not in the unaffected members or in healthy control subjects. CONCLUSION: A rare missense mutation in the PAX6 gene is found in members of a three-generation Chinese family with congenital atypical aniridia. This result contributes to an increase in the phenotypic spectrum caused by PAX6 missense heterozygous variants and provides useful information for the clinical diagnosis of atypical aniridia, which may also contribute to genetic counselling and family planning.

A novel homozygous CLN6 Tyr142Cys variant in a nonconsanguineous family with Kufs disease.

BACKGROUND: Neuronal ceroid lipofuscinoses are a genetically heterogeneous group of inherited lysosomal storage disorders. Kufs disease is the predominant form of neuronal ceroid lipofuscinosis in adults, but it's rare and challenging to diagnose. CASE DESCRIPTION: The proband initially presented with cognitive deterioration and parkinsonian traits. At 35, he was admitted to hospital following a tonic-clonic seizure. Brain magnetic resonance imaging showed atrophy of the cerebral cortex and cerebellum, enlarged ventricles, and thinned corpus callosum. The proband's younger brother and sister were also affected, and the clinical phenotype within the family was consistent. Whole-exome Sequencing of the proband revealed a novel homozygous mutation in CLN6 (NM_017882: c.425A > G, p. Tyr142Cys). Co-segregation analysis revealed that two other affected individuals carried a homozygous mutation at the same locus, with both parents exhibiting heterozygous mutations of c.425A > G. CONCLUSION: Our study not only provides insights into the clinical presentation and development of the disease within the affected family but also expanded the mutational and phenotypical spectrum of the CLN6 gene.