Bi-allelic variants in MRPL49 cause variable clinical presentations, including sensorineural hearing loss, leukodystrophy, and ovarian insufficiency.

Combined oxidative phosphorylation deficiency (COXPD) is a rare multisystem disorder that is clinically and genetically heterogeneous. Genome sequencing identified bi-allelic MRPL49 variants in individuals from nine unrelated families with presentations ranging from Perrault syndrome (primary ovarian insufficiency and sensorineural hearing loss) to severe childhood onset of leukodystrophy, learning disability, microcephaly, and retinal dystrophy. Complexome profiling of fibroblasts from affected individuals revealed reduced levels of the small mitochondrial ribosomal subunits and a more pronounced reduction of the large mitochondrial ribosomal subunits.

Bi-allelic variants in DAP3 result in reduced assembly of the mitoribosomal small subunit with altered apoptosis and a Perrault-syndrome-spectrum phenotype.

The mitochondrial ribosome (mitoribosome) synthesizes 13 protein subunits of the oxidative phosphorylation system encoded by the mitochondrial genome. The mitoribosome is composed of 12S rRNA, 16S rRNA, and 82 mitoribosomal proteins encoded by nuclear genes. To date, variants in 12 genes encoding mitoribosomal proteins are associated with rare monogenic disorders and frequently show combined oxidative phosphorylation deficiency.

Biallelic variants in cause variable clinical presentations, including sensorineural hearing loss, leukodystrophy, and ovarian insufficiency.

Combined oxidative phosphorylation deficiency (COXPD) is a rare multisystem disorder which is clinically and genetically heterogeneous. Genome sequencing identified biallelic variants in individuals from five unrelated families with presentations ranging from Perrault syndrome (primary ovarian insufficiency and sensorineural hearing loss) to severe childhood onset of leukodystrophy, learning disability, microcephaly and retinal dystrophy. Complexome profiling of fibroblasts from affected individuals revealed reduced levels of the small and, a more pronounced reduction of, the large mitochondrial ribosomal subunits.

Biallelic variants in result in reduced assembly of the mitoribosomal small subunit with altered intrinsic and extrinsic apoptosis and a Perrault syndrome-spectrum phenotype.

The mitoribosome synthesizes 13 protein subunits of the oxidative phosphorylation system encoded by the mitochondrial genome. The mitoribosome is composed of 12S rRNA, 16S rRNA and 82 mitoribosomal proteins encoded by nuclear genes. To date, variants in 12 genes encoding mitoribosomal proteins are associated with rare monogenic disorders, and frequently show combined oxidative phosphorylation deficiency.

Homozygous missense variants in BMPR15 can result in primary ovarian insufficiency.

Research Question: Does a genetic condition underlie the diagnosis of primary ovarian insufficiency (POI) in a 13-year-old girl with primary amenorrhoea?

Design: A case report of a next-generation sequencing panel of 24 genes associated with syndromal and non-syndromal POI was conducted.

Results: A homozygous missense variant c.1076C>T, p.

Bi-allelic variants in the mitochondrial RNase P subunit PRORP cause mitochondrial tRNA processing defects and pleiotropic multisystem presentations.

Human mitochondrial RNase P (mt-RNase P) is responsible for 5' end processing of mitochondrial precursor tRNAs, a vital step in mitochondrial RNA maturation, and is comprised of three protein subunits: TRMT10C, SDR5C1 (HSD10), and PRORP. Pathogenic variants in TRMT10C and SDR5C1 are associated with distinct recessive or x-linked infantile onset disorders, resulting from defects in mitochondrial RNA processing. We report four unrelated families with multisystem disease associated with bi-allelic variants in PRORP, the metallonuclease subunit of mt-RNase P.

Biallelic loss of function variants in STAG3 result in primary ovarian insufficiency.

Research Question: Does a genetic condition underlie the diagnosis of primary ovarian insufficiency (POI) in a 21-year-old woman with primary amenorrhoea?

Design: A karyotype and genetic testing for Fragile X syndrome was undertaken. A next-generation sequencing panel of 24 genes associated with syndromal and non-syndromal POI was conducted.

Results: A nonsense variant c.

A Nonadaptive Combinatorial Group Testing Strategy to Facilitate Health Care Worker Screening during the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) Outbreak.

Routine testing for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in health care workers (HCWs) is critical. Group testing strategies to increase capacity facilitate mass population testing but do not prioritize turnaround time, an important consideration for HCW screening. We propose a nonadaptive combinatorial (NAC) group testing strategy to increase throughput while facilitating rapid turnaround.

A recurrent missense variant in HARS2 results in variable sensorineural hearing loss in three unrelated families.

HARS2 encodes mitochondrial histidyl-tRNA synthetase (HARS2), which links histidine to its cognate tRNA in the mitochondrial matrix. Biallelic variants in HARS2 are associated with Perrault syndrome, a rare recessive condition characterized by sensorineural hearing loss in both sexes and primary ovarian insufficiency in 46,XX females. Some individuals with Perrault syndrome have a broader phenotypic spectrum with neurological features, including ataxia and peripheral neuropathy.

Diagnosing and Preventing Hearing Loss in the Genomic Age.

Over the past two decades, significant technological advances have facilitated the identification of hundreds of genes associated with hearing loss. Variants in many of these genes result in severe congenital hearing loss with profound implications for the affected individual and their family. This review collates these advances, summarizing the current state of genomic knowledge in childhood hearing loss.

Marfanoid habitus is a nonspecific feature of Perrault syndrome.

The objective of this study was to report the clinical and biological characteristics of two Perrault syndrome cases in a Moroccan family with homozygous variant c.1565C>A in the LARS2 gene and to establish genotype-phenotype correlation of patients with the same mutation by review of the literature. Whole-exome sequencing was performed.