Deleterious variants in the same gene present in two or more families with overlapping clinical features provide convincing evidence of a disease-gene association; this can be a challenge in the study of ultrarare diseases. To facilitate the identification of additional families, several groups have created "matching" platforms. We describe four individuals from three unrelated families "matched" by GeneMatcher and MatchMakerExchange. Individuals had microcephaly, developmental delay, epilepsy, and recessive mutations in TRIT1. A single homozygous mutation in TRIT1 associated with similar features had previously been reported in one family. The identification of these individuals provides additional evidence to support TRIT1 as the disease-causing gene and interprets the variants as "pathogenic." TRIT1 functions to modify mitochondrial tRNAs and is necessary for protein translation. We show that dysfunctional TRIT1 results in decreased levels of select mitochondrial proteins. Our findings confirm the TRIT1 disease association and advance the phenotypic and molecular understanding of this disorder.

Graphical abstract Graphical abstract key: Wt: weight, Ht: height, OFC: open fontanelle, DD: developmental delay, ID: intellectual disability, EEG: electroencephalogram, OCD: obsessive compulsive disorder, ADHD: attention deficit hyperactivity disorder, ASD: atrial septal defect, VSD: ventricular septal defect, PDA: patent ductus arteriosis, PFO: patent foramen ovale.

Whole-exome sequencing (WES) has increased our ability to analyze large parts of the human genome, bringing with it a plethora of ethical, legal, and social implications. A topic dominating discussion of WES is identification of "secondary findings" (SFs), defined as the identification of risk in an asymptomatic individual unrelated to the indication for the test. SFs can have considerable psychosocial impact on patients and families, and patients with an SF may have concerns regarding genomic privacy and genetic discrimination. The Genetic Information Nondiscrimination Act of 2008 (GINA) currently excludes protections for members of the military. This may cause concern in military members and families regarding genetic discrimination when considering genetic testing. In this report, we discuss a case involving a patient and family in which a secondary finding was discovered by WES. The family members have careers in the U.S. military, and a risk-predisposing condition could negatively affect employment. While beneficial medical management changes were made, the information placed exceptional stress on the family, who were forced to navigate career-sensitive "extra-medical" issues, to consider the impacts of uncovering risk-predisposition, and to manage the privacy of their genetic information. We highlight how information obtained from WES may collide with these issues and emphasize the importance of genetic counseling for anyone undergoing WES.

With only a small number of cases in the medical literature, mosaic trisomy 15 in liveborn infants is very rare. Despite its rarity, similar features among individuals have been described, including intrauterine growth retardation, craniofacial abnormalities and facial dysmorphisms, cardiac disease, and other organ anomalies. Very few liveborns have survived the first year of life. We report here on a term infant with growth restriction and multiple congenital anomalies who was found to have mosaic trisomy 15. The proband presented with some frequently reported findings such as dysmorphic facies and overlapping fingers, and the uncommon finding of whorled hypopigmentation. Previously unreported findings include abnormal cerebral vasculature and dysplastic kidneys. We add this new phenotypic information to widen the spectrum previously reported and provide a review of the literature to date.