genetic screening
Recently Published Documents

Objective. To detect the carrier rates of deafness gene variants in populations in Ningbo and analyze the risk of hereditary hearing loss through concurrent hearing and genetic screening tests. Methods. Two thousand one hundred and seventy-four newborns were enrolled from November 2018 to August 2019. All subjects underwent hearing screening and newborn deafness genetic screening with 15 variants in 4 genes, and the positive sites were simultaneously verified by sequencing. Results. The total carrier rate of genetic variants in Ningbo reached 4.32%, when GJB2 c.235delC was the variant with the highest prevalence (2.12%), approximately accounting for 48.9% of the total carrier frequency. The carrier frequency of SLC26A4 c.919-2A>G was 0.87%, while the most common variant in mitochondrial DNA (mtDNA) MT-RNR1 gene was m.1555A>G, and its carrier frequency was 0.184%. In the OAE testing, 92 newborns passing hearing screening were tested positively for variants in 4 genes, and 2 of 42 newborns who failed in the first hearing test were found to mutate in 4 genes. Conclusion. Herein, the results concerning the carrier rates for deafness gene mutations of Ningbo population are reported. Our study is beneficial to the insight into the deafness genomic epidemiology for deafness genes in Ningbo population and provides the reference for healthcare in Ningbo.

A wide spectrum of neurodegenerative diseases has been associated with pathogenic variants in the PNPLA6 (patatin-like phospholipase domain-containing protein 6) gene, including spastic paraplegia type 39, Gordon—Holmes, Boucher—Neuhauser, Oliver—Mc Farlane, and Laurence—Moon syndromes. These syndromes present variable and overlapping clinical symptoms, encompassing cerebellar ataxia, hypogonadotropic hypogonadism, chorioretinal dystrophy, spastic paraplegia, muscle wasting, peripheral neuropathy, and cognitive impairment. In the present study, we performed a wide genetic screening in 292 patients presenting with ataxia or spastic paraplegia using a probe-based customized gene panel, covering >200 genes associated with spinocerebellar diseases. We identified six novel and four recurrent PNPLA6 gene variants in eight patients (2.7%). Six patients presented an infantile or juvenile onset (age <18), and two patients had an adult onset. Cerebellar ataxia was observed in seven patients and spastic paraplegia in one patient. Progression of cerebellar symptoms was slow in all patients, who retained ambulation even after a mean disease duration of 15 years. Brain MRI showed cerebellar atrophy in 6/8 patients, more pronounced in superior and dorsal vermis lobules (I to VII). Additional clinical features included hypogonadotropic hypogonadism (5/8), growth hormone deficiency (2/8), peripheral axonal neuropathy (4/8), cognitive impairment (3/8), chorioretinal dystrophy (2/8), and bilateral vestibular areflexia with a reduced visual vestibule-ocular reflex (1/8). In accordance with previous studies, chorioretinal dystrophy was the most frequent presenting symptom in early onset patients, hypogonadotropic hypogonadism in juvenile onset cases, and cerebellar ataxia in adult patients. One patient had an initial clinical presentation compatible with Cerebellar Ataxia with Neuropathy and Vestibular Areflexia Syndrome (CANVAS), but no pathological expansions in the RFC1 gene. In conclusion, patients with PNPLA6 variants present a variable age of onset spanning from infancy to adulthood, and each clinical symptom has an age-dependent manifestation thus requiring a multi-systemic diagnostic approach. The description of patients presenting very late-onset cerebellar ataxia suggests that PNPLA6 genetic screening should also be considered in the diagnostic workout of adult cerebellar ataxia.

Background: Transthyretin amyloid cardiomyopathy (ATTR-CM) is one of the most common types of cardiac amyloidosis. Amyloid cardiomyopathy more commonly affects men, elderly, and 3% to 4% of the African-American population. ATTR-CM suspicion and diagnosis is challenging; however, awareness of the disease is increasing, and best practices to identify it are being proposed. The approach to suspected cases of ATTR-CM relies on the presence of heart failure, red flag signs and symptoms, and age >65 or >70 for men and women respectively. Little is known about cases when it presents in early ages. Case: We report a 62-year-old African American male with past medical history of hyperlipidemia, prostate cancer, hypertension, bilateral carpal tunnel surgery that had debuted with a cardiac arrhythmia at age 55 and was diagnosed with heart failure several years later. Restrictive cardiomyopathy was suspected, and genetic screening was sent for ATTRm which confirmed a pathogenic trasnthyretin gene mutation. Endomyocardial biopsy was performed which confirmed cardiac amyloid deposition. Discussion: ATTR-CM is a rare disease with an increasing prevalence. Cases with out of proportion signs and symptoms of heart failure with preserved ejection fractions should raise the suspicion of ATTR-CM despite age.

Myocardial infarction (MI) is a complicated pathology triggered by numerous environmental and genetic factors. Understanding the effect of epigenetic regulation mechanisms on the cardiovascular disease would advance the field and promote prophylactic methods targeting epigenetic mechanisms. Genetic screening guides individualised MI therapies and surveillance. The present review reported the latest development on the epigenetic regulation of MI in terms of DNA methylation, histone modifications, and microRNA-dependent MI mechanisms and the novel therapies based on epigenetics.

Escape is an evolutionarily conserved and essential avoidance response. Considered to be innate, most studies on escape responses focused on hard-wired circuits. We report here that peptidergic signaling is an integral and necessary component of the Caenorhabditis elegans escape circuit. Combining genetic screening, electrophysiology, and calcium imaging, we reveal that a neuropeptide NLP-18 and its cholecystokinin receptor CKR-1 enable the escape circuit to execute a full omega turn, the last motor step where the animal robustly steers away from its original trajectory. We demonstrate in vivo and in vitro that CKR-1 is a Gq protein-coupled receptor for NLP-18. in vivo, NLP-18 is mainly secreted by the gustatory sensory neuron (ASI) to activate CKR-1 in the head motor neuron (SMD) and the turn-initiating interneuron (AIB). Removal of NLP-18, removal of CKR-1, or specific knockdown of CKR-1 in SMD or AIB neurons lead to shallower turns hence less robust escape steering. Consistently, the Ca2+ transients elevation of head motor neuron SMD during escape steering is attenuated upon the removal of NLP-18 or CKR-1. in vitro, synthetic NLP-18 directly evokes CKR-1-dependent currents in oocytes and CKR-1-dependent Ca2+ transients in SMD. Thus, cholecystokinin signaling modulates an escape circuit to generate robust escape steering.

Background: Hemophilia A (HA) is an X-linked recessive bleeding disorder with a high rate of genetic heterogeneity. The present study was conducted on a large cohort of Iranian HA patients and data obtained from databases. Methods: A total of 622 Iranian HA patients from 329 unrelated families who had been referred to a medical genetics laboratory in Tehran from 2005 to 2019, were enrolled in this retrospective, observational study. Genetic screening of pathogenic variants of the F8 gene was performed using inverse shifting PCR, direct sequencing, and multiplex ligation-dependent amplification (MLPA). Point mutation frequencies in different exons were analyzed for our samples as well as 6031 HA patients whose data were recorded in a database. Results: A total of 144 different pathogenic or likely pathogenic variants including 29 novel variants were identified. A strategy to decrease costs of genetic testing of HA was suggested based on this finding. Conclusion: This study provides comprehensive information on F8 pathogenic/likely pathogenic variants in Iranian HA patients which improves the spectrum of causative mutations and can be helpful to clinicians and medical geneticists in counseling and molecular diagnosis of HA.