Genetics Papers & Publications

Purpose: Congenital hypogonadotropic hypogonadism (CHH) is a rare genetic disorder mostly characterized by gonadotropins release and/or action deficiencies. Both isolated (idiopathic hypogonadotropic hypogonadism) and syndromic (Kallmann) forms are identified depending on the olfactory ability. Clinical and genetic heterogeneities of CHH have been widely explored, thus improving our understanding of the disease's pathophysiology. This work aims to (1) provide a detailed clinical and hormonal description of normosmic CHH patients and (2) identify the mutation linked to the studied phenotype. Participants and methods: We investigated three affected patients with normosmic CHH, belonging to a consanguineous Tunisian family. Patients underwent an insulin-induced hypoglycemia test. We performed whole exome sequencing to identify the causal mutation. Results: At first diagnosis, a total gonadotropic deficiency was identified in all patients. The insulin-induced hypoglycemia test has also revealed a reduced cortisol secretion and complete growth hormone deficiency. At 20.8 years, one female exhibited a spontaneous recovery of the hypothalamic-pituitary-adrenal axis function, unlike her affected siblings who still depend on corticosteroid replacement therapy. Herein, we identified a novel homozygous nonstop mutation (c.1195T>C) in KISS1R gene in all affected subjects. This mutation led to the substitution of the physiologic stop codon by an arginine (p.X399R). Conclusions: Our study highlights the importance of the KISS1R signaling, in gonadotropin-releasing hormone neurons, in the control of reproductive function. Additionally, our data suggests a complex central and peripheral metabolic control of puberty, through the hypothalamic KISS1R signaling. We suggest a mutual link between the hypothalamic-pituitary-gonadal, -adrenal, and -somatotropic axes.

Mariam moalla

Introduction/aims: Maturity-Onset Diabetes of the Young (MODY) is a monogenic non-autoimmune diabetes with 14 different genetic forms. MODY-related mutations are rarely found in the Tunisian population. Here, we explored MODY related genes sequences among seventeen unrelated Tunisian probands qualifying the MODY clinical criteria. Materials and methods: The GCK and HNF1A genes were systematically analyzed by direct sequencing in all probands. Then, clinical exome sequencing of 4,813 genes was performed on three unrelated patients. Among them, 130 genes have been reported to be involved in the regulation of glucose metabolism, β-cell development, differentiation and function. All identified variants were analyzed according to their frequencies in the GnomAD database and validated by direct sequencing. Results: We identified the previously reported GCK mutation (rs1085307455) in one patient. The clinical features of the MODY2 proband were similar to previous reports. In this study, we revealed rare and novel alterations in GCK (rs780806456) and ABCC8 (rs201499958) genes with uncertain significance. We also found two likely benign alterations in HNF1A (rs1800574) and KLF11 (rs35927125) genes with minor allele frequencies similar to those depicted in public databases. No pathogenic variants have been identified through clinical exome analysis. Conclusions: The most appropriate patients were selected, following a strict clinical screening approach, for genetic testing. However, the known MODY1-13 genes could not explain most of the Tunisian MODY cases, suggesting the involvement of unidentified genes in the majority of Tunisian affected families.

Mariam moalla

Cystic fibrosis is a challenging disease which creates many complications. The impact caused from cystic fibrosis on an adolescent is a challenging phase for their lives. Negative impacts like the society’s pressure, anxiety and depression are few common reasons that are being unspoken and ignored due to complexity of the disease. This study is aimed to identify the necessary gaps and educate the necessary policy makers and CF center health care team to have a better understanding about the context of the aftermath of cystic fibrosis and enhance better patient care. More over this systematic review also points out the main trends in this field of study. Qualitative study and quantitative are prominently used research methods to gain an understanding the about the gaps in the research. However, there is still a scarcity of quantitative and mixed research methods. Furthermore, limitations such as language, cultural influences were identified whilst going through the analysis. Overall through the information given in the following in this study more information regarding that warrants answers can be identified which will lead to proper care towards the teenagers who suffers from cystic fibrosis.

Chanitha Pemasena

Gaucher Disease (GD) is the most common lysosomal storage disorder. The prevalence of GD is approximately 1/100,000, and type III GD accounts for 5% of cases. [1] It is an autosomal recessive disease due to a GBA gene mutation, leading to glucocerebrosidase enzyme deficiency. [1,2] Gaucher disease (GD) is categorized into three types according to clinical presentation: [3] Type I, which is non-neuronopathic and most common, particularly among Ashkenazi Jews; Type II, which is acute neuronopathic and marked by significant neurological involvement and high mortality rates; and Type III, which is subacute neuronopathic, exhibiting both systemic and neurological symptoms. In this report, we discuss a 24-year-old man from Libya diagnosed with GD type III. His diagnosis was established at the age of one due to symptoms including pallor, poor appetite, and hepatosplenomegaly. Laboratory tests indicated a hemoglobin level of 5.6 g/dL, chitotriosidase activity of 18,742 μmol/L, and an angiotensin-converting enzyme level of 251 UI/L. Genetic analysis confirmed a homozygous L444P mutation. He underwent splenectomy at the age of three, and enzyme replacement therapy (ERT) was administered intermittently with regular follow-ups until 2011. In December 2023, the patient experienced two weeks of abdominal pain, distension, and fatigue. A physical examination revealed ascites, dilated abdominal veins, and an enlarged liver and spleen.

Karishma