Further Evidence for RFWD3 Gene Causing Fanconi Anemia Complementation Group W: Detailed Clinical Report of the Second Case in the Literature.

Introduction: Fanconi anemia (FA) is a heterogeneous genetic disorder that is characterized by progressive bone marrow failure, congenital malformations, predisposition to malignancy, and short stature. The RFWD3 gene was recently associated with FA complementation group W, and only 1 patient is reported in the literature so far. Case Presentation: Here, we report the second patient, a 10-year-old male, who has failure to thrive, central nervous system abnormalities, bilateral radial ray defects, urogenital anomalies, facial dysmorphism, and thrombocytopenia. The patient was suspected to have FA according to the aforementioned findings, and the homozygous c.1501C>T variant in the RFWD3 gene was detected by whole-exome sequencing. The diepoxybutane test and mitomycin C-induced peripheral blood cultures revealed 0.46 and 0.90 chromosomal breaks, respectively. Conclusion: In this article, clinical findings of the second patient with FA complementation group W are discussed in detail, aiming to expand the clinical and molecular spectrums of the disease.

Screening of Mutations in Maturity-onset Diabetes of the Young-related Genes and RFX6 in Children with Autoantibody-negative Type 1 Diabetes Mellitus.

Objective: Maturity-onset diabetes of the young (MODY) is the most common type of monogenic diabetes. To date, mutations have been identified in 14 different genes of patients with a clinical diagnosis of MODY. This study screened mutations in 14 MODY-related genes and the regulator factor X6 (RFX6) gene in children. Materials and Methods: The presence of clinical features of MODY and negative results for three autoantibody markers of T1DM in children and adolescents were used as inclusion criteria for genetic testing. The screening panel for next-generation sequencing included 14 MODY-related genes (GCK, HNF4A, HNF1A, HNF1B, PDX1, NEUROD1, KLF11, CEL, PAX4, INS, BLK, ABCC8, KCNJ11, and APPL1) and the RFX6 gene. Results: Twenty-four different variants in MODY-related genes were identified in 49 children diagnosed with autoantibody-negative type 1 diabetes mellitus (T1DM). A 12 variants were classified as P/LP while 12 were interpreted as variant of unknown significance (VUS). Nine of the pathogenic or likely pathogenic variants were found in GCK, two in HNF1B, and one in ABCC8. Three variants were novel, and one was a de novo variant. All of the variants, except one, showed heterozygotic inheritance. Conclusion: This study screened mutations in the 14 MODY-related genes and the regulatory factor X6 (RFX6) gene in Turkish children diagnosed with autoantibody-negative type 1 diabetes mellitus (T1DM). The frequencies of the MODY subtypes differed from previous reports. Although GCK-MODY was the most frequent mutation in Turkish children, similar to previous studies, the second most prevalent MODY subtype was HNF1B-MODY. This study also established three additional novel mutations in different MODY genes.

A case of familial recurrent 17q12 microdeletion syndrome presenting with severe diabetic ketoacidosis.

BACKGROUND: Heterozygous intragenic mutations of the hepatocyte nuclear factor 1 homeobox b gene (HNF1B) located on chromosome 17 and microdeletion of 17q12 region (17q12MD) leads to the complete loss of this gene, which causes renal cystic disease, diabetes mellitus (MODY5), hypomagnesemia, hyperuricemia, liver enzyme abnormalities, genital tract abnormalities and exocrine pancreatic insufficiency. In addition, patients with 17q12MD also have facial dysmorphism, neuro-developmental and neuropsychiatric disorders. CASE: A 16-year-old girl with obesity and mild facial dysmorphism was admitted to the hospital with symptoms of diabetes that started two days prior to her admission. She was diagnosed with severe diabetic ketoacidosis and treated accordingly. She had been followed up with the diagnoses of multicystic renal disease, hydronephrosis, hepatosteatosis, hypomagnesemia and hyperuricemia since the age of six. She had mild intellectual disability. Her menarche started two months ago. Cranial magnetic resonance imaging revealed mild diffuse cerebral and cerebellar atrophy and a partial empty sella. Her mother had diabetes, hypomagnesemia and mild intellectual disability and her maternal grandfather and uncle had diabetes. Her grandfather also had renal cystic disease. All of them are on oral antidiabetic medication. The genetic analysis of the patient and her mother revealed a loss of 1.6 megabases in chromosome 17q12. CONCLUSIONS: MODY5 should be kept in mind in patients with diabetes who present with extra pancreatic findings, especially with renal cystic disease, more over, a genetic analysis including the study of 17q12MD should be carried out in patients who present with additional neuropsychiatric findings. Ketoacidosis can be seen in patients with MODY5. Ketoacidosis and renal anomalies and dysfunction are factors that increase and affect the severity of each other in these patients.

Wiedemann-Steiner Syndrome: A Rare Differential Diagnosis of Neurodevelopmental Delay and Dysmorphic Features.

Wiedemann-Steiner syndrome (WSS) is a rare genetic disorder characterized by dysmorphic features, neurodevelopmental delay, growth retardation, and hypertrichosis cubiti. It is caused by pathogenic variants in the KMT2A gene. Here, we report a child with WSS presented with neurodevelopmental delay. Genetic analysis revealed a heterozygous c.2312dupC (p.Ser774Valfs*11) variant at the KMT2A gene that was classified as pathogenic in dbSNP (rs1057518649). To the best of our knowledge, this is the first patient of WSS from Turkey. This case draws attention to the diagnosis of WSS in children with neurodevelopmental delay.

Assessment of clinical characteristics of cardiac amyloidosis as a potential underlying etiology in patients diagnosed with heart failure with preserved ejection fraction.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is heterogeneous clinical syndrome. Transthyretin cardiac amyloidosis (CA) is an underdiagnosed cause of HFpEF. Red flags are extremely useful for suspecting CA. AIMS: We aimed to evaluate the frequency of cardiac and extracardiac manifestations of CA in HFpEF patients based on red flags. METHODS: Baseline characteristics of 85 patients were recorded during admission. Electrocardiogram and echocardiography were performed. All patients were examined for red flags. Cardiac scintigraphy was performed in 85 patients. RESULTS: The mean (standard deviation [SD]) age of the study group was 67.9 (9.8) years, and 52 (61.2%) patients were female. At least 1 red flag was observed in 67% of HFpEF patients. Only 4 of the patients had more than 3 red flags. The mean number of red flags in a patient with HFpEF was 1.3. Extracardiac clinical red flags were observed in only 9 (10.5%) patients. Cardiac clinical red flags were extremely rare. An electrocardiographic red flag was detected in 2 out of 10 patients and an echocardiographic red flag in 4 out of 10 patients with HFpEF. Scintigraphy showed that 17.6% of all patients have had a grade 2 or 3 cardiac uptake. The patients with wild-type transthyretin CA had twice as many red flags as those without. CONCLUSION: The results of the study showed that patients diagnosed with HFpEF had an average of 1.3 red flags suggestive of CA. In real life, extracardiac red flags are rare, while electrocardiographic and echocardiographic red flags are more common in patients with HFpEF.

Spectrum of PAH gene mutations and genotype-phenotype correlation in patients with phenylalanine hydroxylase deficiency from Turkey.

OBJECTIVES: The aim of our study was to define the genotype-phenotype correlations of mutations in the PAH gene among the Turkey's Central Anatolian region. METHODS: Demographic characteristics of 108 patients with hyperphenylalaninemia (HPA) and 94 patients whose diagnosis was confirmed by PAH gene analysis (Sanger DNA Sequence Analysis and Next-Generation Sequencing) were determined retrospectively. Blood phenylalanine levels were analyzed using the high-performance liquid chromatography method. RESULTS: Mild HPA-not-requiring-treatment (NT) was found in 50.9% of the patients, and a classical phenylketonuria (PKU) phenotype was found in 25.9%. Forty-seven types of variants were identified. The predominant variants were p.Ala403Val (9.9%), p.Ala300Ser (9.4%), and c.1066-11G>A (splicing) (9.4%). Missense mutations accounted for 68% of mutations and attenuated the clinical impact; splice variations were found in 14.8% of cases with severe features. The p.Thr380Met allele was specific to the mild HPA-NT group. The c.1066-11G>A (splicing) allele was associated with classical PKU, whereas the p.Arg408Trp allele was linked to severe symptoms. Three variations of unknown clinical significance were discovered: c.706+4A>T (splicing), c.843-5T>C (splicing), and p.Thr323=. Of these variants, the patient who was homozygous for the c.843-5T>C (splicing) allele related to the classical PKU phenotype. 70% of the patients who underwent tetrahydrobiopterin (BH4) test were responsive. Phenotypes that responded to BH4 treatment were mostly mild phenotypes. CONCLUSIONS: The PAH genotype is the main factor that determines the phenotype of PKU. Establishing the relationship between the identified genetic mutations and phenotypic characteristics will provide very important data for each patient in terms of the specific management style.

NDE1-related disorders: A recurrent NDE1 pathogenic variant causing Lissencephaly 4 can also be associated with microhydranencephaly.

NudE Neurodevelopment Protein 1 (NDE1) gene encodes a protein required for microtubule organization, mitosis, and neuronal migration. Biallelic pathogenic variants of NDE1 gene are associated with structural central nervous system abnormalities, specifically microlissencephaly and microhydranencephaly. The root of these different phenotypes remains unclear. Here, we report a 20-year-old male patient referred to our clinics due to severe microcephaly, developmental delay, spastic quadriplegia, and dysmorphic features. The cranial computed tomography revealed abnormal brain structure and excess of cerebrospinal fluid, consistent with microhydranencephaly. A homozygous c.684_685del, p.(Pro229TrpfsTer85) change in NDE1 gene was found by clinical exome analysis. The variant has previously been reported in individuals with microlissencephaly, therefore we propose that the same variant within the gene may cause either microlissencephaly or microhydranencephaly phenotypes. There are only a few papers about NDE1-related disorders in the literature and the patient we described is important to clarify the phenotypic spectrum of the disease.

An Anomaly with Potential as a New Prognostic Marker in CLL with del(13q): Gain of 16p13.3.

Deletion 13q [del(13q)] is a favorable prognostic marker if it is detected as a sole abnormality in chronic lymphocytic leukemia (CLL). However the clinical courses of cases with isolated del(13q) are quite heterogeneous. In our study, we investigated copy number variations (CNVs), loss of heterozygosity (LOH), and the size of del(13q) in 30 CLL patients with isolated del(13q). We used CGH+SNP microarrays in order to understand the cause of this clinical heterogeneity. We detected del(13q) in 28/30 CLL cases. The size of the deletion varied from 0.34 to 28.81 Mb, and there was no clinical effect of the deletion size. We found new prognostic markers, especially the gain of 16p13.3. These markers have statistically significant associations with short time to first treatment and advanced disease stage. Detecting both CNVs and LOH at the same time is an advantageous feature of aCGH+SNP. However, it is very challenging for the array analysis to detect mosaic anomalies. Therefore, it is very important to confirm the results by FISH. In our study, we detected approximately 9% mosaic del(13q) by microarray. In addition, the gain of 16p13.3 may affect the disease prognosis in CLL. However, additional studies with more patients are needed to confirm these results.

A pediatric BAL case with double Ph chromosomes and trisomy 5.

Biphenotypic acute leukemias (BAL) are known as a type of leukemia involving cells with myeloid and along with lymphoid origin, in which genomic changes are detected. It has been stated that the most common genomic changes in BAL are t(9;22) and the translocations of the 11q23 region, these anomalies cause poor prognostic effects. We detected trisomy 5 (+5) in addition to the double Ph chromosome in a case where we investigated the genomic changes using molecular and conventional cytogenetic methods. Bone marrow transplantation was planned due to the poor response to prednisone. According to the information we have obtained, our report will be the first article to discuss the aberrations found in addition to the Ph chromosome in BAL and the effect of these aberrations on prognosis. However, the double observation of the Ph chromosome, which has a poor prognostic effect, is expected to affect the prognosis more negatively, this case will contribute to the literature in terms of trisomy 5. We think that more case reports are needed to reveal the anomalies and their prognostic significance in BAL.

Frequency of frontotemporal dementia-related gene variants in Turkey.

Just as its clinical heterogeneity, genetic basis of Frontotemporal dementia (FTD) is also diverse and multiple molecular pathways are thought to be involved in disease pathogenesis. In the present study, FTD- related genes were evaluated in a Turkish cohort of 175 index FTD patients with a gene panel including GRN, MAPT, TARDBP, FUS, CHMP2B and VCP genes. Potential genetic associations were prospected in 16 patients (9.1%); five variants (p.(Gly35Glufs) and p.(Cys253Ter) in GRN; p.(Arg95Cys) in VCP; p.(Met405Val) in TARDBP and p.(Pro636Leu) in MAPT) were classified as pathogenic (P) or likely pathogenic (LP), in four familial and one sporadic patients. Three novel variants in MAPT, CHMP2B and FUS were also identified in familial cases. The most common pathogenic variants were observed in the GRN gene with a frequency of 1.14% (2/175) and this rate was 4.57% (8/175), including variants of uncertain significance (VUS). In this study with the largest cohort of Turkish FTD patients, GRN and MAPT variants were identified as the most common genetic associations; and rare causes like VCP, TARDBP, CHMP2B and FUS variants are recommended to be considered in patients with compatible clinical findings.

Which prognostic marker is responsible for the clinical heterogeneity in CLL with 13q deletion?

BACKGROUND: Deletion of 13q14 [del(13q)] is the most common cytogenetic change (50%) in chronic lymphoblastic leukemia (CLL), and it is a good prognostic factor if it is detected as a sole aberration by FISH. However, it is observed the clinical course of CLL cases with del(13q) are quite heterogeneous and the responsible for this clinical heterogeneity has not been established yet. Some investigators suggest type II deletion (include RB1 gene) is associated with more aggressive clinical course. Also, it is suggested that the deletion burden and the deletion type have a prognostic effect. In this study, we aimed to investigate the effect of RB1 gene deletion, deletion burden and deletion type on overall survival (OS), disease stage and time to first treatment (TTFT) in patients with isolated del(3q). Sixty eight cases, detected isolated del(13q) were included in the study. Also, RB1 deletion was analyzed from peripheral blood of them using FISH. RESULTS: RB1 deletion was detected in 41% of patients, but there was no statistically significant difference between RB1 deletion and TTFT, stage and OS (p > 0.05). At same time, statistically significant difference was detected between high del(13q) (> 80%) and TTFT (p < 0.05). CONCLUSION: The statistical analysis of our data regarding to the association between RB1 deletion and deletion type, TTFT, disease stage, and OS has not confirmed type II deletion or biallelic deletion cause poor prognosis. However, our data supports the deletion burden has a prognostic effect. More studies are needed to elucidate the cause of the clinical heterogeneity of CLL cases with del(13q).

The association between repeat number in C9orf72 and phenotypic variability in Turkish patients with frontotemporal lobar degeneration.

Frontotemporal lobar degeneration (FTLD) describes a group of progressive brain disorders. The expansion of a noncoding GGGGCC (G4C2) hexanucleotide repeat in the C9orf72 gene is a major cause of both familial FTLD and amyotrophic lateral sclerosis. The aim of this study was to determine the prevalence of C9orf72 G4C2-repeat expansion in a Turkish population with FTLD and to determine its effects on the phenotype. The G4C2 expansion in the C9orf72 gene was analyzed in 100 cases of FTLD without mutations of the MAPT, PGRN, CHMP2B, VCP, TARDBP, and FUS genes and 100 age-matched healthy controls by using repeat-primed polymerase chain reaction and fragment length analysis techniques. A possible pathogenic repeat (≥30) was found in one of the familial cases (1/33), but none of the sporadic cases. The difference in the allele length between the cases and controls was statistically significant (p < 0.01). Intermediate (20-30) repeats were detected in 4% of our cases. Patients with psychotic symptoms appear to be enriched for intermediate and possibly pathogenic repeats. To determine whether the intermediate and ≥30-repeat allele carriers shared the C9orf72 risk haplotype, we examined rs4879515 and rs3849942 in all samples and family members of patients with possibly pathogenic alleles. We identified at least one risk allele for each single-nucleotide polymorphism in all intermediate and possibly pathogenic repeat carriers. We observed that ≥8 unit repeats were strongly correlated with the tagging risk alleles for both single-nucleotide polymorphisms (p < 0.001). To our knowledge, this is the first study to evaluate C9orf72 G4C2 repeats in Turkish patients with FTLD. The present findings suggest that pathogenic expansions of the C9orf72 repeat are uncommon in Turkish patients with FTLD, but intermediate repeats may be a risk factor for FTLD and act as a genetic modifying factor for psychotic symptoms.