Evaluation of chromosomal abnormalities in the postnatal cohort: A single-center study on 14,242 patients.

BACKGROUND AND AIM: Chromosomal analysis is a laboratory technique used to examine the chromosomes of an individual, offering insights into chromosome numbers, structures, and arrangements to diagnose and comprehend genetic diseases. This retrospective study provides a comprehensive understanding of the distribution by indications in a large cohort of 14,242 patients and the frequency of chromosomal abnormalities in different clinical populations. METHOD: The study examined various indications for karyotype evaluation, with recurrent pregnancy loss being the most common indication, followed by intellectual disability, dysmorphic features, congenital anomalies, and developmental delay. RESULTS: The overall chromosomal abnormality rate was found to be 5.4%, with numerical abnormalities accounting for the majority of cases (61.7%). Trisomies, particularly trisomy 21, were the most frequent numerical abnormalities. In terms of structural abnormalities, inversions and translocations were the most commonly identified. The rates of chromosomal anomalies varied in specific indications such as amenorrhea, disorders of sex development, and Turner syndrome. The study also highlighted significant differences between males and females in the presence of chromosomal abnormalities across certain indications. Males exhibited a higher incidence of chromosomal abnormalities in cases of Down syndrome and infertility, whereas females showed higher abnormalities in terms of recurrent pregnancy loss. CONCLUSION: While this study provides valuable insights into the frequency and distribution of chromosomal abnormalities, it has limitations, including its retrospective design and reliance on data from a single medical genetics department. Nevertheless, the findings emphasize the importance of karyotype analysis in diagnosing chromosomal disorders and providing appropriate management, while also pointing to potential gender-related variations in chromosomal abnormalities that warrant further investigation.

A Case of Short Stature Caused by a Mutation in the ACAN Gene.

Introduction: Aggrecanopathies are rare disorders associated with idiopathic short stature. They are caused by pathogenic changes in the ACAN gene located on chromosome 15q26. In this study, we present a case of short stature caused by mutations in the ACAN gene. Case Presentation: A 3-year-3-month-old male patient was referred to us because of his short stature. Physical examination revealed proportional short stature, frontal bossing, macrocephaly, midface hypoplasia, ptosis in the right eye, and wide toes. When the patient was 6 years and 3 months old, his bone age was compatible with 7 years of age. The patient underwent clinical exome sequencing and a heterozygous nonsense c.1243G>T, p.(Glu415*) pathogenic variant was detected in the ACAN gene. The same variant was found in his phenotypically similar father. Our patient is the second case with ptosis. Discussion: ACAN gene mutation should be considered in the differential diagnosis of patients with idiopathic short stature. The development and widespread use of next-generation sequencing technology has increased the diagnostic and treatment possibilities.

Case Report: A Novel Mutation Leading to 11-ß Hydroxylase Deficiency in a Female Patient.

BACKGROUND: 11ß hydroxylase deficiency (11ßOHD) ranks as the second most common enzyme deficiency that causes congenital adrenal hyperplasia. Depending on the severity of the enzyme deficiency, it can lead to cortisol deficiency, androgen excess and hypertension due to increased mineralocorticoid precursor levels. Many different types of mutations in the CYP11B1 gene located on chromosome 8q24.3 have been shown to cause 11ßOHD. Here, we report a novel missense mutation that leads to 11ßOHD in a female patient. CASE PRESENTATION: A 35-year-old female patient was admitted to the Endocrinology Department with a complaint of abdominal pain. The patient had a history of genital reconstruction surgery twice in childhood. On physical examination, an abdominal mass was detected. Laboratory examination of the patient revealed low levels of cortisol, potassium and high levels of ACTH, 11-deoxycortisol and androstenedione, suggesting 11ßOHD. Genotyping showed a novel homozygous missense mutation (c.1385T>C L462P variant) detected on the 8th chromosome where the CYP11B1 gene is located. Glucocorticoid therapy was commenced for the patient whose diagnosis of 11ßOHD was confirmed by both hormonal and genetic tests. A mass originating from the left adrenal gland with the largest diameter of 7 cm was compatible with myelolipoma. CONCLUSION: In this case report, we aimed to contribute to the literature by reporting a new missense mutation in the CYP11B1 gene, leading to classic type 11ßOHD that has not been described before.

Neonatal Diabetes, Congenital Hypothyroidism, and Congenital Glaucoma Coexistence: A Case of GLIS3 Mutation

Neonatal diabetes and congenital hypothyroidism (CH) syndrome is a rare condition caused by homozygous or compound heterozygous mutations in the GLIS3 gene. Small for gestational age, congenital glaucoma, polycystic kidney disease, cholestatic hepatic fibrosis, pancreatic exocrine insufficiency, developmental delay, dysmorphic facial features, sensorineural deafness, osteopenia, and skeletal anomalies are other accompanying phenotypic features in the 22 cases described so far. We present a male patient with neonatal diabetes, CH, congenital glaucoma, developmental delay, and facial dysmorphism. During the patient's 17-year follow-up, no signs of exocrine pancreatic insufficiency, liver and kidney diseases, deafness, osteopenia, and bone fracture were observed. A homozygous exon 10-11 deletion was detected in the GLIS3 gene. We report one of the oldest surviving GLIS3 mutation case with main findings of neonatal diabetes and CH syndrome to contribute to the characterization of the genotypic and phenotypic spectra of the syndrome.

Congenital Myasthenic Syndromes in Turkey: Clinical and Molecular Characterization of 16 Cases With Three Novel Mutations.

BACKGROUND: Congenital myasthenic syndromes (CMS) are composed of numerous hereditary disorders involving genetic mutations in proteins essential to the integrity of neuromuscular transmission. The symptoms of CMS vary according to the age at onset of symptoms, and the type and severity of muscle weakness. Effective treatment and genetic counseling depend upon the underlying pathogenic molecular mechanism and subtype of CMS. METHODS: A retrospective and cross-sectional study was performed with 16 patients with a genetically confirmed diagnosis of CMS to share our experience with clinical symptoms, demographic data, genetic variants, and treatments applied. RESULTS: Sixteen patients with a specific CMS genetic diagnosis (three novel mutations) were identified, including CHRNE (n = 7), DOK7 (n = 2), AGRN (n = 2), RAPSN (n = 1), CHRNA1 (n = 1), CHRNB1 (n = 1), CHAT (n = 1), and SCN4A (n = 1). Age at onset of symptoms ranged from the neonatal period to 12 years. Genetic diagnosis was confirmed between the ages of three months and 17 years. A significant delay was determined between the onset of symptoms and genetic diagnosis of the disease. CONCLUSIONS: This study highlights the importance of genetic testing in CMS. Due to the rarity of CMS, more cases will be recognized and reported as the use of laboratory and genetic testing accelerates. We hope that our experience will grow and contribute further to the literature as clinical follow-up and treatment increase.

Diagnosing Alström syndrome in a patient followed up with syndromic obesity for years.

Alström syndrome (AS) is a rare autosomal recessive monogenic disorder caused by mutations of the Alström syndrome 1 (ALMS1) gene, located on chromosome 2p13. It is a progressive multisystemic disease characterized mostly by obesity, sensorineural hearing loss, visual impairments, cardiomyopathy, insulin resistance and/or type 2 diabetes mellitus (T2DM), metabolic dysfunctions, non-alcoholic fatty liver disease, and chronic progressive kidney disease. Generally, the first clinical symptoms of the disease appear in the first years of life with a major variation of onset age. In this study, we aimed to examine the molecular diagnosis of a 6-year-old patient with suspected AS clinical symptoms. After applying clinical exome sequencing (CES) in the patient we found a homozygous deletion in exon 8 at the ALMS1 gene (c.2311_2312del). We identified a homozygous frameshift mutation. The reported variant was pathogenic according to the criteria of the American College of Medical Genetics and Genomics (ACMG). Thus, the patient was diagnosed with AS as a result of the combined clinical phenotype and genetic tests results. We hope the variant we found can expand the spectrum of ALMS1 variants in AS.

Clinical and molecular evaluation of MEFV gene variants in the Turkish population: a study by the National Genetics Consortium.

Familial Mediterranean fever (FMF) is a monogenic autoinflammatory disorder with recurrent fever, abdominal pain, serositis, articular manifestations, erysipelas-like erythema, and renal complications as its main features. Caused by the mutations in the MEditerranean FeVer (MEFV) gene, it mainly affects people of Mediterranean descent with a higher incidence in the Turkish, Jewish, Arabic, and Armenian populations. As our understanding of FMF improves, it becomes clearer that we are facing with a more complex picture of FMF with respect to its pathogenesis, penetrance, variant type (gain-of-function vs. loss-of-function), and inheritance. In this study, MEFV gene analysis results and clinical findings of 27,504 patients from 35 universities and institutions in Turkey and Northern Cyprus are combined in an effort to provide a better insight into the genotype-phenotype correlation and how a specific variant contributes to certain clinical findings in FMF patients. Our results may help better understand this complex disease and how the genotype may sometimes contribute to phenotype. Unlike many studies in the literature, our study investigated a broader symptomatic spectrum and the relationship between the genotype and phenotype data. In this sense, we aimed to guide all clinicians and academicians who work in this field to better establish a comprehensive data set for the patients. One of the biggest messages of our study is that lack of uniformity in some clinical and demographic data of participants may become an obstacle in approaching FMF patients and understanding this complex disease.

Detection of mutations in CML patients resistant to tyrosine kinase inhibitor: imatinib mesylate therapy.

Imatinib mesylate, a tyrosine kinase inhibitor, is the first choice in chronic myeloid leukemia treatment. However, resistance to imatinib may develop with time and in some cases, patients may not respond at all to imatinib. Progressive resistance to imatinib therapy is often due to mutations in the BCR/ABL region. Within the scope of our study 124 patients were evaluated via pyrosequencing between 2015 and 2020. In this regard, 32 patients who have a partial response and have no response to imatinib therapy were included in the study. In addition, next-generation sequencing (NGS) analysis was performed on 15 patients who were resistant to imatinib treatment according to the molecular follow-up reports. With pyrosequencing, 5 cases out of a total of 124 were found to be positive. This means that approximately 4.03% of the proportion is positive. But when we examined only 32 patients who have a partial response and have no response to imatinib therapy this rate is rising 15.6%. NGS analysis was performed with 15 patients who have no mutation with pyrosequencing of 32 patients and VUS (Variant of Uncertain Significance) mutation was detected in one. In this study, our aim was to determine the mutations of the BCR/ABL and to evaluate the mutations by NGS and pyrosequencing. Our study is important in terms of comparing the pyrosequencing with NGS mutation rates, drawing attention to the clinical importance of log reduction.