Biallelic CRELD1 variants cause a multisystem syndrome, including neurodevelopmental phenotypes, cardiac dysrhythmias, and frequent infections.

PURPOSE: We sought to delineate a multisystem disorder caused by recessive cysteine-rich with epidermal growth factor-like domains 1 (CRELD1) gene variants. METHODS: The impact of CRELD1 variants was characterized through an international collaboration utilizing next-generation DNA sequencing, gene knockdown, and protein overexpression in Xenopus tropicalis, and in vitro analysis of patient immune cells. RESULTS: Biallelic variants in CRELD1 were found in 18 participants from 14 families. Affected individuals displayed an array of phenotypes involving developmental delay, early-onset epilepsy, and hypotonia, with about half demonstrating cardiac arrhythmias and some experiencing recurrent infections. Most harbored a frameshift in trans with a missense allele, with 1 recurrent variant, p.(Cys192Tyr), identified in 10 families. X tropicalis tadpoles with creld1 knockdown displayed developmental defects along with increased susceptibility to induced seizures compared with controls. Additionally, human CRELD1 harboring missense variants from affected individuals had reduced protein function, indicated by a diminished ability to induce craniofacial defects when overexpressed in X tropicalis. Finally, baseline analyses of peripheral blood mononuclear cells showed similar proportions of immune cell subtypes in patients compared with healthy donors. CONCLUSION: This patient cohort, combined with experimental data, provide evidence of a multisystem clinical syndrome mediated by recessive variants in CRELD1.

Relationship satisfaction in adults with phenylketonuria is positively associated with following recommended treatment, having a partner involved in management, and maintaining good health.

RATIONALE: Phenylketonuria (PKU) is a metabolic condition that requires treatment for life. There is increasing evidence that chronic illnesses put strain on relationships and marriages. However, no studies have examined the unique factors that metabolic conditions have on affected individuals and their relationship satisfaction. We surveyed a population of adult patients with PKU and assessed how management, treatment, and lifestyle factors impact their relationship satisfaction. PURPOSE: The purpose of our study was to explore whether factors such as involvement of partner in PKU management, impact of challenges unique to PKU (e.g., diet, family planning, mood disturbances), and PKU treatment types were associated with the degree of relationship satisfaction. METHOD: We surveyed adult patients with PKU (n = 82) who were either currently in or had previously been in a long-term relationship. We developed a 78-question survey that included unique questions regarding lifestyle, treatment, and management of their PKU in addition to a validated Relationship Assessment Score. Questions included single choice, multiple choice, and 3 open-ended questions. RESULTS: We found that higher relationship satisfaction was associated with increased partner involvement, increased health, and adherence to recommended PKU treatments. Participants utilizing both diet and pharmaceutical treatment had the highest relationship satisfaction. Finally, participants who reported that their PKU did not contribute to the ending of a previous relationship reported higher relationship satisfaction scores. CONCLUSION: This study suggests that involvement of partners in the management and treatment of a chronic illness and adherence to recommended treatments can significantly improve relationship satisfaction.

Germline variants in tumor suppressor FBXW7 lead to impaired ubiquitination and a neurodevelopmental syndrome.

Neurodevelopmental disorders are highly heterogenous conditions resulting from abnormalities of brain architecture and/or function. FBXW7 (F-box and WD-repeat-domain-containing 7), a recognized developmental regulator and tumor suppressor, has been shown to regulate cell-cycle progression and cell growth and survival by targeting substrates including CYCLIN E1/2 and NOTCH for degradation via the ubiquitin proteasome system. We used a genotype-first approach and global data-sharing platforms to identify 35 individuals harboring de novo and inherited FBXW7 germline monoallelic chromosomal deletions and nonsense, frameshift, splice-site, and missense variants associated with a neurodevelopmental syndrome. The FBXW7 neurodevelopmental syndrome is distinguished by global developmental delay, borderline to severe intellectual disability, hypotonia, and gastrointestinal issues. Brain imaging detailed variable underlying structural abnormalities affecting the cerebellum, corpus collosum, and white matter. A crystal-structure model of FBXW7 predicted that missense variants were clustered at the substrate-binding surface of the WD40 domain and that these might reduce FBXW7 substrate binding affinity. Expression of recombinant FBXW7 missense variants in cultured cells demonstrated impaired CYCLIN E1 and CYCLIN E2 turnover. Pan-neuronal knockdown of the Drosophila ortholog, archipelago, impaired learning and neuronal function. Collectively, the data presented herein provide compelling evidence of an F-Box protein-related, phenotypically variable neurodevelopmental disorder associated with monoallelic variants in FBXW7.