The Phenotypic and Genotypic Spectrum of CSF1R-Related Disorder in China.

BACKGROUND: Colony-stimulating factor 1 receptor (CSF1R)-related disorder (CRD) is a rare autosomal dominant disease. The clinical and genetic characteristics of Chinese patients have not been elucidated. OBJECTIVE: The objective of the study is to clarify the core features and influence factors of CRD patients in China. METHODS: Clinical and genetic-related data of CRD patients in China were collected. Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Sundal MRI Severity Score were evaluated. Whole exome sequencing was used to analyze the CSF1R mutation status. Patients were compared between different sexes, mutation types, or mutation locations. RESULTS: A total of 103 patients were included, with a male-to-female ratio of 1:1.51. The average age of onset was (40.75 ± 8.58). Cognitive impairment (85.1%, 86/101) and parkinsonism (76.2%, 77/101) were the main clinical symptoms. The most common imaging feature was bilateral asymmetric white matter changes (100.0%). A total of 66 CSF1R gene mutants (22 novel mutations) were found, and 15 of 92 probands carried c.2381 T > C/p.I794T (16.30%). The MMSE and MoCA scores (17.0 [9.0], 11.90 ± 7.16) of female patients were significantly lower than those of male patients (23.0 [10.0], 16.36 ± 7.89), and the white matter severity score (20.19 ± 8.47) of female patients was significantly higher than that of male patients (16.00 ± 7.62). There is no statistical difference in age of onset between male and female patients. CONCLUSIONS: The core manifestations of Chinese CRD patients are progressive cognitive decline, parkinsonism, and bilateral asymmetric white matter changes. Compared to men, women have more severe cognitive impairment and imaging changes. c.2381 T > C/p.I794T is a hotspot mutation in Chinese patients. © 2024 International Parkinson and Movement Disorder Society.

Regulation of epinephrine biosynthesis in HRAS-mutant paragangliomas.

The biochemical phenotype of paragangliomas (PGLs) is highly dependent on the underlying genetic background and tumor location. PGLs at extra-adrenal locations usually do not express phenylethanolamine N-methyltransferase (PNMT), the enzyme required for epinephrine production, which was explained by the absence of glucocorticoids. PGLs with pathogenic variants (PVs) in Harvey rat sarcoma viral oncogene homolog (HRAS) can occur in or outside of the adrenal, but always synthesize epinephrine independently of the localization. Here, we characterize the signaling pathways through which PVs in HRAS influence PNMT expression. Catecholamines, cortisol, and transcriptional features of PGL tissues with known genetic background were analyzed. Genetically modified rat pheochromocytoma cells carrying PVs in Hras were generated and analyzed for regulation of Pnmt expression. Elevated epinephrine contents in PGLs with PVs in HRAS were accompanied by enrichment in mitogen-activated protein kinase (MAPK) signaling compared to PGLs with PVs in genes that activate hypoxia pathways. In vitro, Hras PVs increased Pnmt expression and epinephrine biosynthesis through increased phosphorylation of stimulatory protein 1 via MAPK signaling. Here, we provide a molecular mechanism that explains the PV-dependent epinephrine production of PGLs.

Phenotype-genotype mapping reveals the betaine-triggered L-arginine overproduction mechanism in Escherichia coli.

The production phenotype improvement of industrial microbes is extremely needed and challenging. Environmental factors optimization provides insightful ideas to trigger the superior production phenotype by activating potential genetic determiners. Here, phenotype-genotype mapping was used to dissect the betaine-triggered L-arginine overproduction mechanism and mine beneficial genes for further improving production phenotype. The comparative transcriptomic analysis revealed a novel role for betaine in modulating global gene transcription. Guided by this finding, 4 novel genes (cynX, cynT, pyrB, and rhaB) for L-arginine biosynthesis were identified via reverse engineering. Moreover, the rhaB deletion was demonstrated as a common metabolic engineering strategy to improve ATP pool in E. coli. By combinatorial genes manipulation, the L-arginine titer and yield increased by 17.9% and 28.9% in a 5-L bioreactor without betaine addition. This study revealed the molecular mechanism of gene transcription regulation by betaine and developed a superior L-arginine overproducer that does not require betaine.

Targeted locus amplification reveals heterogeneity between and within CFTR genotypes and association with CFTR function in patient-derived intestinal organoids.

BACKGROUND: Cystic fibrosis (CF) disease severity can be highly variable, even between people with CF (pwCF) with similar genotypes. Here we use patient-derived intestinal organoids to study the influence of genetic variation within the cystic fibrosis transmembrane conductance regulator (CFTR) gene on CFTR function. METHODS: Organoids of F508del/class I, F508del/S1251N and pwCF with only one detected CF-causing mutation were cultured. Allele-specific CFTR variation was investigated using targeted locus amplification (TLA), CFTR function was measured using the forskolin-induced swelling assay and mRNA levels were quantified using RT-qPCR. RESULTS: We were able to distinguish CFTR genotypes based on TLA data. Additionally, we observed heterogeneity within genotypes, which we were able to link to CFTR function for S1251N alleles. CONCLUSIONS: Our results indicate that the paired analysis of CFTR intragenic variation and CFTR function can gain insights in the underlying CFTR defect for individuals where the disease phenotype does not match the CFTR mutations detected during diagnosis.

Temperature instability of a mutation at a multidomain junction in Na,K-ATPase isoform ATP1A3 (p.Arg756His) produces a fever-induced neurological syndrome.

ATP1A3 encodes the α3 isoform of Na,K-ATPase. In the brain, it is expressed only in neurons. Human ATP1A3 mutations produce a wide spectrum of phenotypes, but particular syndromes are associated with unique substitutions. For arginine 756, at the junction of membrane and cytoplasmic domains, mutations produce encephalopathy during febrile infections. Here we tested the pathogenicity of p.Arg756His (R756H) in isogenic mammalian cells. R756H protein had sufficient transport activity to support cells when endogenous ATP1A1 was inhibited. It had half the turnover rate of wildtype, reduced affinity for Na+, and increased affinity for K+. There was modest endoplasmic reticulum retention during biosynthesis at 37 °C but little benefit from the folding drug phenylbutyrate (4-PBA), suggesting a tolerated level of misfolding. When cells were incubated at just 39 °C, however, α3 protein level dropped without loss of ß subunit, paralleled by an increase of endogenous α1. Elevated temperature resulted in internalization of α3 from the surface along with some ß subunit, accompanied by cytoplasmic redistribution of a marker of lysosomes and endosomes, lysosomal-associated membrane protein 1. After return to 37 °C, α3 protein levels recovered with cycloheximide-sensitive new protein synthesis. Heating in vitro showed activity loss at a rate 20- to 30-fold faster than wildtype, indicating a temperature-dependent destabilization of protein structure. Arg756 appears to confer thermal resistance as an anchor, forming hydrogen bonds among four linearly distant parts of the Na,K-ATPase structure. Taken together, our observations are consistent with fever-induced symptoms in patients.

Exploring and expanding the phenotype and genotype diversity in seven Chinese families with spondylo-epi-metaphyseal dysplasia.

Spondylo-epi-metaphyseal dysplasia (SEMD) is a heterogeneous group of disorders with different modes of inheritance and is characterized by disproportionate or proportionate short stature. To date, more than 30 disease-causing genes have been identified, and different types of SEMD exhibit greatly overlapping clinical features, which usually complicate the diagnosis. This study was performed to expand the clinical and molecular spectrum of SEMD among Chinese subjects and to explore their potential phenotype-genotype relations. We enrolled seven families including 11 affected patients with SEMD, and their clinical, radiographic, and genetic data were carefully analyzed. All the seven probands showed different degrees of short stature, and each of them exhibited additional specific skeletal manifestations; four probands had extraosseous manifestations. X-rays of the seven probands showed common features of SEMD, including vertebral deformities, irregular shape of the epiphysis, and disorganization of the metaphysis. Seven variants were identified in TRPV4 (c.694C> T, p.Arg232Cys), COL2A1 (c.654 + 1G > C; c.3266_3268del, p.Gly1089del), CCN6 (c.396 T> G, p.Cys132Trp; c.721 T>C, p.Cys241Arg), SBDS (c.258 + 2T> C), and ACAN (c.1508C> A, p.Thr503Lys) genes, and two of them were novel. Two families with TRPV4 variants showed considerable intrafamily and interfamily heterogeneities. In addition, we reported one case of SEMD with a severe phenotype caused by ACAN gene mutation. Our study expands the phenotype and genetic spectrum of SEMD and provides evidence for the phenotype-genotype relations, aiding future molecular and clinical diagnosis as well as procreative management of SEMD.

Identification of New Copy Number Variation and the Evaluation of a CNV Detection Tool for NGS Panel Data in Polish Familial Hypercholesterolemia Patients.

Familial hypercholesterolemia (FH) is an inherited, autosomal dominant metabolic disorder mostly associated with disease-causing variant in LDLR, APOB or PCSK9. Although the dominant changes are small-scale missense, frameshift and splicing variants, approximately 10% of molecularly defined FH cases are due to copy number variations (CNVs). The first-line strategy is to identify possible pathogenic SNVs (single nucleotide variants) using multiple PCR, Sanger sequencing, or with more comprehensive approaches, such as NGS (next-generation sequencing), WES (whole-exome sequencing) or WGS (whole-genome sequencing). The gold standard for CNV detection in genetic diagnostics are MLPA (multiplex ligation-dependent amplification) or aCGH (array-based comparative genome hybridization). However, faster and simpler analyses are needed. Therefore, it has been proposed that NGS data can be searched to analyze CNV variants. The aim of the study was to identify novel CNV changes in FH patients without detected pathogenic SNVs using targeted sequencing and evaluation of CNV calling tool (DECoN) working on gene panel NGS data; the study also assesses its suitability as a screening step in genetic diagnostics. A group of 136 adult and child patients were recruited for the present study. The inclusion criteria comprised at least "possible FH" according to the Simon Broome diagnostic criteria in children and the DLCN (Dutch Lipid Clinical Network) criteria in adults. NGS analysis revealed potentially pathogenic SNVs in 57 patients. Thirty selected patients without a positive finding from NGS were subjected to MLPA analysis; ten of these revealed possibly pathogenic CNVs. Nine patients were found to harbor exons 4−8 duplication, two harbored exons 6−8 deletion and one demonstrated exon 9−10 deletion in LDLR. To test the DECoN program, the whole study group was referred for bioinformatic analysis. The DECoN program detected duplication of exons 4−8 in the LDLR gene in two patients, whose genetic analysis was stopped after the NGS step. The integration of the two methods proved to be particularly valuable in a five-year-old girl presenting with extreme hypercholesterolemia, with both a pathogenic missense variant (c.1747C>T) and exons 9−10 deletion in LDLR. This is the first report of a heterozygous deletion of exons 9 and 10 co-occurring with SNV. Our results suggest that the NGS-based approach has the potential to identify large-scale variation in the LDLR gene and could be further applied to extend CNV screening in other FH-related genes. Nevertheless, the outcomes from the bioinformatic approach still need to be confirmed by MLPA; hence, the latter remains the reference method for assessing CNV in FH patients.

The Growing Spectrum of DADA2 Manifestations-Diagnostic and Therapeutic Challenges Revisited.

Deficiency of Adenosine Deaminase Type 2 (DADA2) is a rare autosomal recessive inherited disorder with a variable phenotype including generalized or cerebral vasculitis and bone marrow failure. It is caused by variations in the adenosine deaminase 2 gene (ADA2), which leads to decreased adenosine deaminase 2 enzyme activity. Here we present three instructive scenarios that demonstrate DADA2 spectrum characteristics and provide a clear and thorough diagnostic and therapeutic workflow for effective patient care. Patient 1 illustrates cerebral vasculitis in DADA2. Genetic analysis reveals a compound heterozygosity including the novel ADA2 variant, p.V325Tfs*7. In patient 2, different vasculitis phenotypes of the DADA2 spectrum are presented, all resulting from the homozygous ADA2 mutation p.Y453C. In this family, the potential risk for siblings is particularly evident. Patient 3 represents pure red cell aplasia with bone marrow failure in DADA2. Here, ultimately, stem cell transplantation is considered the curative treatment option. The diversity of the DADA2 spectrum often delays diagnosis and treatment of this vulnerable patient cohort. We therefore recommend early ADA2 enzyme activity measurement as a screening tool for patients and siblings at risk, and we expect early steroid-based remission induction will help avoid fatal outcomes.

G507D mutation in FUS gene causes familial amyotrophic lateral sclerosis with a specific genotype-phenotype correlation.

Mutations in FUS gene have been described classically in young ALS patients with aggressive disease course. Here we report a large family carrying a missense mutation c.1520 G>A in FUS gene with a tight association with an atypical FUS-ALS phenotype. A 60-year-old man with unilateral leg involvement at onset showed very slow disease progression with selective posterior legs atrophy, tracing his aunt's disease history. His father and uncle died for ALS after a long disease course. Another patient with a 14 years history of ALS with the same phenotype, was found to belong to the same family. In all cases, genetic analysis of FUS gene revealed a missense mutation c.1520 G>A (p.G507D) inherited with a heterozygous pattern. Co-segregation of p.G507D mutation and a specific disease phenotype within the family, characterised by predominant involvement at the lower limbs, slow progression, late bulbar and respiratory failure, demonstrates pathogenicity of this mutation, establishes a well-defined genotype-phenotype correlation and expands the clinical spectrum of heterogeneity in FUS-ALS.

Congenital myasthenic syndrome: Correlation between clinical features and molecular diagnosis.

OBJECTIVES: To present phenotype features of a large cohort of congenital myasthenic syndromes (CMS) and correlate them with their molecular diagnosis. METHODS: Suspected CMS patients were divided into three groups: group A (limb, bulbar or axial weakness, with or without ocular impairment, and all the following: clinical fatigability, electrophysiology compatible with neuromuscular junction involvement and anticholinesterase agents response), group B (limb, bulbar or axial weakness, with or without ocular impairment, and at least one of additional characteristics noted in group A) and group C (pure ocular syndrome). Individual clinical findings and the clinical groups were compared between the group with a confirmed molecular diagnosis of CMS and the group without molecular diagnosis or with a non-CMS molecular diagnosis. RESULTS: Seventy-nine patients (68 families) were included in the cohort: 48 in group A, 23 in group B and 8 in group C. Fifty-one were considered confirmed CMS (30 CHRNE, 5 RAPSN, 4 COL13A1, 3 DOK7, 3 COLQ, 2 GFPT1, 1 CHAT, 1 SCN4A, 1 GMPPB, 1 CHRNA1), 7 probable CMS, 5 non-CMS and 16 unsolved. The chance of a confirmed molecular diagnosis of CMS was significantly higher for group A and lower for group C. Some individual clinical features, alterations on biopsy and electrophysiology enhanced specificity for CMS. Muscle imaging showed at least mild alterations in the majority of confirmed cases, with preferential involvement of soleus, especially in CHRNE CMS. CONCLUSIONS: Stricter clinical criteria increase the chance of confirming a CMS diagnosis, but may lose sensitivity, especially for some specific genes.

Importancia del uso de la genómica en el diagnóstico precoz de la esclerosis tuberosa, reporte de caso / The importance of the use of genomics in early diagnosis of tuberous sclerosis: case report

Introduccion: La esclerosis tuberosa en un trastorno raro con manifestaciones clínicas multisistémicas que puede comprometer órganos vitales como riñón pulmón y corazón por lo que requiere un diagnóstico precoz para brindar un tratamiento oportuno y dirigido mejorando el pronóstico y disminuyendo la morbimortalidad atribuida a esta patología. Objetivo: Establecer la importancia del uso de la genómica y la correlación fenotipo-genotipo para el diagnóstico, tratamiento, seguimiento, pronóstico, asesoramiento genético de la esclerosis tuberosa. Materiales y métodos: Reporte de caso de paciente 15 años con angiofibromas corporales, hamartoma retiniano, angiomiolipoma derecho y alteraciones de estudios de neuroimagen sin convulsiones ni trastornos neuroconductuales, se sospecho clínicamente de esclerosis tuberosa con confirmación genética al tener una variante patogénica en estado de heterocigosis en el gen TSC2. Resultados: Se encontró una deleción heterocigota patogénica que cambia una citosina en la posición 2.539 del ADNc del gen TSC2 (c.2539delC), que lleva a un codón de parada prematuro en el aminoácido 893 (p. Leu847Cysfs*47) en una proteína de 1.807 aminoácidos con significado clínico patogénico. Conclusiones: El complejo esclerosis tuberosa constituye una enfermedad huérfana para Colombia dada la baja prevalencia poblacional, con una alta carga en morbilidad y mortalidad debido al compromiso multisistémico. Su confirmación se realiza mediante métodos moleculares ­ genómicos que permiten establecer correlación fenotipo-genotipo dada la variabilidad en las variantes reportadas en este gen y los diferentes grados de expresión fenotípicos en los individuos, lo cual nos orienta a buscar signos y síntomas de compromiso de órganos o sistemas posiblemente afectados acercándonos a una medicina personalizada y de precisión.

Introduction: Tuberous sclerosis is a rare disorder with multisystemic clinical manifestations that can compromise vital organs such as the kidney, lung and heart, which requires early diagnosis to provide timely and targeted treatment, improving the prognosis and reducing the morbidity and mortality attributed to these pathologies. Objective: To establish the importance of the use of genomics and the phenotype-genotype correlation for the diagnosis, treatment, follow-up, prognosis, genetic counseling of tuberous sclerosis. Materials and methods : Case report of a 15 year old patient with body angiofibromas, retinal hamartoma, right angiomyolipoma and alterations in neuroimaging studies without seizures or neurobehavioral disorders, clinically suspected of tuberous sclerosis with genetic confirmation by having a pathogenic variant in heterozygosity in the TSC2 gene. Results: A pathogenic heterozygous deletion was found in which a cytosine is changed at position 2539 of the TSC2 gene cDNA (c.2539delC), leading to a premature stop codon at amino acid 893 ( p.Leu847Cysfs*47) into a protein of 1,807 amino acids with pathogenic clinical significance. Conclusions: Tuberous sclerosis complex is an orphan disease for Colombia given the low population prevalence, with a high burden of morbidity and mortality due to multisystem involvement. Its confirmation is performed by molecular-genomic methods that allow establishing phenotype-genotype correlation given the variability in the variants reported in this gene and the different degree of phenotypic expression in individuals, which guides us to look for signs and symptoms of involvement of organs or systems possibly affected, approaching a personalized and precision medicine.

Identification of BRCA2 Cis Double Heterozygous Breast Cancer Cases Using Whole Exome Sequencing: Phenotypic Expression and Impact on Personalized Oncology.

BRCA1 and BRCA2 are the most commonly mutated breast cancer susceptibility genes that convey a high risk of breast and ovarian cancer. Most BRCA1 or BRCA2 mutation carriers have inherited a single heterozygous mutation. In recent years, very rare cases with biallelic or trans double heterozygous mutations on BRCA1 and or BRCA2 have been identified and seem to be associated with distinctive phenotypes. Given that this genotype-phenotype correlation in cancer predisposing hereditary conditions is of relevance for oncological prevention and genetic testing, it is important to investigate these rare BRCA genotypes for better clinical management of BRCA mutation carriers. Here we present the first report on Cis double heterozygosity (Cis DH) on BRCA2 gene identified using Whole exome sequencing (WES) in a Tunisian family with two BRCA2 mutations namely: c.632-1G>A and c.1310_1313DelAAGA that are both reported as pathogenic in ClinVar database. Subsequent analysis in 300 high-risk Tunisian breast cancer families detected this Cis double heterozygous genotype in 8 additional individuals belonging to 5 families from the same geographic origin suggesting a founder effect. Moreover, the observed Cis DH seems to be associated with an early age of onset (mean age = 35.33 years) and severe phenotype of the disease with high breast cancer grade and multiple cancer cases in the family. The identification of unusual BRCA genotypes in this Tunisian cohort highlights the importance of performing genetic studies in under-investigated populations. This will also potentially help avoiding erroneous classifications of genetic variants in African population and therefore avoiding clinical misdiagnosis of BRCA related cancers. Our findings will also have an impact on the genetic testing and the clinical management of North African breast cancer patients as well as patients from different other ethnic groups in regard to several emerging target therapies such as PARP inhibitors.

Phylogenetic analysis of combined lobular and ductal carcinoma of the breast.

Breast cancer manifests in diverse forms, with particular reference to various cell types harboring different mutations and gene expression profiles. To elucidate the clonal relationship between cancer cells in tumors composed of both ductal and lobular phenotypes, two combined lobular and ductal carcinoma (CLDC) cases were analyzed, including one mixed ductal­lobular carcinoma (MDL) lesion, by direct sequencing of the mitochondrial DNA D­loop, digital PCR targeting of chromosomes 1q and 16q, as well as next­generation sequencing. DNA was extracted from formalin­fixed paraffin­embedded tissue sections of different histological types, including invasive ductal carcinoma, invasive lobular carcinoma, ductal carcinoma in situ, lobular carcinoma in situ, flat epithelial atypia, non­neoplastic mammary gland and extramammary organs, using laser­assisted microdissection. Mutations detected by the comprehensive cancer panel were validated by SYBR green allele­specific quantitative PCR (RRM1, AKT1, PIK3CA, RALGDS, EGFR, TP53, IL21R, DPYD, SGK1, CDH1, TIMP3 and KMT2C). CLDC, which shared the basic genetic alterations of 1q gain or 16q loss, progresses to invasive lobular or ductual carcinoma with the accumulation of further mutations. Cancer cells contained in an MDL lesion shared closely related genetic alterations, suggesting that these cells have the same origin, despite different histological features, namely 'lobular' or 'ductal'. By contrast, multiple lesions located away from the main tumor, diagnosed as CLDC (excluding an MDL lesion) were not always identical with different genetic alterations, despite being diagnosed as ductal carcinoma in situ. Thus, MDL should be defined as a distinct category separate from CLDC, whose components of 'lobular' and 'ductal' may have the same cellular origin.

ATP7B variant spectrum in a French pediatric Wilson disease cohort.

BACKGROUND/AIM: The spectrum of ATP7B variants varies significantly according to geographic distribution, and there is insufficient data on the variants observed in the French population. METHODS: Clinical data of 113 children included in the French WD national registry were gathered from March 01, 1995 to July 01, 2020. Data included epidemiological, clinical, laboratory, genetics. RESULTS: Diagnosis was made at a mean age of 11.0 ± 4.1 years (range 1-18 years). At diagnosis, 91 patients (79.8 %) had hepatic manifestations, 18 (15.8 %) presented neurological manifestations, and 4 patients (3.5 %) were asymptomatic. Only 29 patients (25 %) were homozygous for a variant. We have found a total of 102 different variants including 14 novel variants. Recurrent variant p.His1069Gln was the most prevalent, n = 31 alleles (14,2%), with only seven homozygous; in contrast 55% of variants are identified in only one family. 45% were truncating variants. In respect of mutated exon, the three most prevalent were exon 14 (16.5%), exon 8 (13.8%), and exon 3 (11.5%). When considering patients with two Nonsense / Frameshift variants as a group and those with two Missense variants, we found significantly lower ceruloplasmin for the former: 2.8 ± 0.7 mg/dl vs 8.4 ± 5mg/dl (p<0.05). CONCLUSION: p.His1069Gln is the most frequent variant (14,2%) and exons 14, 8, and 2 of the ATP7B gene account for 41.7% of total variants. However, there is significant heterogeneity in the French population concerning the other ATP7B variants. Nonsense / Frameshift variants were associated with lower ceruloplasmin levels.

Terminal osseous dysplasia with pigmentary defects and cardiomyopathy caused by a novel FLNA variant.

Terminal osseous dysplasia with pigmentary defects (TODPD), also known as digitocutaneous dysplasia, is one of the X-linked filaminopathies caused by a variety of FLNA-variants. TODPD is characterized by skeletal defects, skin fibromata and dysmorphic facial features. So far, only a single recurrent variant (c.5217G>A;p.Val1724_Thr1739del) in FLNA has found to be responsible for TODPD. We identified a novel c.5217+5G>C variant in FLNA in a female proband with skeletal defects, skin fibromata, interstitial lung disease, epilepsy, and restrictive cardiomyopathy. This variant causes mis-splicing of exon 31 predicting the production of a FLNA-protein with an in-frame-deletion of 16 residues identical to the miss-splicing-effect of the recurrent TODPD c.5217G>A variant. This mis-spliced transcript was explicitly detected in heart tissue, but was absent from blood, skin, and lung. X-inactivation analyses showed extreme skewing with almost complete inactivation of the mutated allele (>90%) in these tissues, except for heart. The mother of the proband, who also has fibromata and skeletal abnormalities, is also carrier of the FLNA-variant and was diagnosed with noncompaction cardiomyopathy after cardiac screening. No other relevant variants in cardiomyopathy-related genes were found. Here we describe a novel variant in FLNA (c.5217+5G>C) as the second pathogenic variant responsible for TODPD. Cardiomyopathy has not been described as a phenotypic feature of TODPD before.

Mevalonate Kinase-Associated Diseases: Hunting for Phenotype-Genotype Correlation.

Mevalonate kinase-associated diseases (MKAD) are caused by pathogenic mutations in the mevalonate kinase gene (MVK) and encompass several phenotypically different rare and hereditary autoinflammatory conditions. The most serious is a recessive systemic metabolic disease called mevalonic aciduria, and the most recently recognized is disseminated superficial actinic porokeratosis, a dominant disease limited to the skin. To evaluate a possible correlation between genotypes and (1) the different MKAD clinical subtypes or (2) the occurrence of severe manifestations, data were reviewed for all patients with MVK variants described in the literature (N = 346), as well as those referred to our center (N = 51). The genotypes including p.(Val377Ile) (homozygous or compound heterozygous) were more frequent in mild systemic forms but were also sometimes encountered with severe disease. We confirmed that amyloidosis was more prevalent in patients compound heterozygous for p.(Ile268Thr) and p.(Val377Ile) than in others and revealed new associations. Patients homozygous for p.(Leu264Phe), p.(Ala334Thr) or compound heterozygous for p.(His20Pro) and p.(Ala334Thr) had increased risk of severe neurological or ocular symptoms. All patients homozygous for p.(Leu264Phe) had a cataract. The variants associated with porokeratosis were relatively specific and more frequently caused a frameshift than in patients with other clinical forms (26% vs. 6%). We provide practical recommendations focusing on phenotype-genotype correlation in MKAD that could be helpful for prophylactic management.

Tuberous Sclerosis Complex: Early Screening and Infant Outcome in NICU.

OBJECTIVE: We describe the clinical and genetic features, drug use and neuropsychiatric disorders of infants diagnosed with tuberous sclerosis complex (TSC) within 3 months of age at a neonatal intensive care unit (NICU) to better understand the different outcomes from early screening. METHODS: In this retrospective study, we consisted of 42 infants with a definitive TSC diagnosis by genetic criteria (TSC1 = 8, TSC2 = 34). The different phenotypes and outcomes between patients with TSC1 and TSC2 mutations were analyzed. RESULTS: The most common initial presenting features of TSC were cortical tubers on magnetic resonance imaging (50%), hypomelanotic macules on skin (47.61%) and spasm (42.85%), when they were diagnosed. Following disease progression to time of follow-up 1 year later, we found that the rate of epilepsy increased from 42.85% to 75.61% and that of cardiac rhabdomyoma increased from 28.57% to 43.9%. The median age at first presentation was 7.84 ± 1.88 months. We also found that 54.83% of patients on medication were seizure free for over 1 year, and that 43.9% of patients have intellectual disability. In total, 42 variants of TSC were detected, including 12 novel variants. We found no evidence of an association between different clinical features and their outcomes among patients with different gene mutations. CONCLUSION: Early diagnosis of TSC in NICU opens a window of opportunity for early, more effective treatment of epilepsy as well as reduces the risk of neurological conditions.

A KRT6A and a Novel KRT16 Gene Mutations in Chinese Patients with Pachyonychia Congenita.

BACKGROUND: Pachyonychia congenita (PC) is a rare, autosomal dominant genodermatosis characterized by palmoplantar keratoderma, nail dystrophy, cystic lesions, follicular hyperkeratosis, mucosal leukokeratoses, hyperhidrosis, hoarseness, and, rarely, natal teeth. Five keratin genes, KRT6A, KRT6B, KRT6C, KRT16 and KRT17, have been found to be associated with PC. METHODS: Using polymerase chain reaction and Sanger sequencing techniques, the purpose of the present study was to investigate the clinical features associated with PC and discover disease-associated variants. The KRT6A, KRT16, KRT17, and KRT6B exonic and flanking region sequences were amplified and directly sequenced to detect mutations. RESULTS: Across two independent instances of PC, we identified a previously reported c.1393T>C (p.Tyr465His) mutation in exon 7 of KRT6A, and a novel c.1237G>C (p.Glu413Gln) heterozygous missense mutation in exon 6 of the KRT16 gene. CONCLUSION: Through phenotype-genotype analysis among PC pedigrees, confirmed diagnoses of PC-K6a and PC-K16 were made in the two patients who presented with symptoms of PC. A new pathogenic mutation site in PC-K16 was potentially discovered.

Clinical and Immunological Characteristics of 63 Patients with Chronic Granulomatous Disease: Hacettepe Experience.

BACKGROUND: Chronic granulomatous disease (CGD), one of the phagocytic system defects, is the primary immunodeficiency caused by dysfunction of the NADPH oxidase complex which generates reactive oxygen species (ROS), which are essential for killing pathogenic microorganisms, especially catalase-positive bacteria and fungi. OBJECTIVE: The objective of our study was to assess the clinical and laboratory characteristics, treatment modalities, and prognosis of patients with CGD. METHODS: We retrospectively reviewed 63 patients with CGD who have been diagnosed, treated, and/or followed-up between 1984 and 2018 in Hacettepe University, Ankara, in Turkey, as a developing country. RESULTS: The number of female and male patients was 26/37. The median age at diagnosis was 3.8 (IQR: 1.0-9.6) years. The rate of consanguinity was 63.5%. The most common physical examination finding was lymphadenopathy (44/63), growth retardation (33/63), and hepatomegaly (27/63). One adult patient had squamous cell carcinoma of the lung. The most common infections were lung infection (53/63), skin abscess (43/63), and lymphadenitis (19/63). Of the 63 patients with CGD, 6 patients had inflammatory bowel disease (IBD). Twelve of the 63 patients died during follow-up. CYBA, NCF1, CYBB, and NCF2 mutations were detected in 35%, 27.5%, 25%, and 12.5% of the patients, respectively. CONCLUSION: We identified 63 patients with CGD from a single center in Turkey. Unlike other cohort studies in Turkey, due to the high consanguineous marriage rate in our study group, AR form of CGD was more frequent, and gastrointestinal involvement were found at relatively lower rates. The rate of patients who treated with HSCT was lower in our research than in the literature. A majority of the patients in this study received conventional prophylactic therapies, which highlight on the outcome of individuals who have not undergone HSCT.

Impact of a Gap Junction Protein Alpha 4 Variant on Clinical Disease Phenotype in F508del Homozygous Patients With Cystic Fibrosis.

BACKGROUND: Lung disease phenotype varies widely even in the F508del (homozygous) genotype. Leukocyte-driven inflammation is important for pulmonary disease pathogenesis in cystic fibrosis (CF). Blood cytokines correlate negatively with pulmonary function in F508del homozygous patients, and gap junction proteins (GJA) might be related to the influx of blood cells into the lung and influence disease course. We aimed to assess the relationship between GJA1/GJA4 genotypes and the clinical disease phenotype. METHODS: One-hundred-and-sixteen homozygous F508del patients (mean age 27 years, m/f 66/50) were recruited from the CF centers of Bonn, Frankfurt, and Amsterdam. Sequence analysis was performed for GJA1 and GJA4. The clinical disease course was assessed over 3 years using pulmonary function tests, body mass index, Pseudomonas aeruginosa colonization, diabetes mellitus, survival to end-stage lung disease, blood and sputum inflammatory markers. RESULTS: Sequence analysis revealed one clinically relevant single nucleotide polymorphism. In this GJA4 variant (rs41266431), homozygous G variant carriers (n = 84/116; 72.4%) had poorer pulmonary function (FVC% pred: mean 78/86, p < 0.040) and survival to end-stage lung disease was lower (p < 0.029). The frequency of P. aeruginosa colonization was not influenced by the genotype, but in those chronically colonized, those with the G/G genotype had reduced pulmonary function (FVC% pred: mean 67/80, p < 0.049). Serum interleukin-8 (median: 12.4/6.7 pg/ml, p < 0.052) and sputum leukocytes (2305/437.5 pg/ml, p < 0.025) were higher for the G/G genotype. CONCLUSIONS: In carriers of the A allele (27.6%) the GJA4 variant is associated with significantly better protection against end-stage lung disease and superior pulmonary function test results in F508del homozygous patients. This SNP has the potential of a modifier gene for phenotyping severity of CF lung disease, in addition to the CFTR genotype. CLINICAL TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov, number NCT04242420, retrospectively on January 24th, 2020.