Outcomes of 4 years of molecular genetic diagnosis on a panel of genes involved in premature aging syndromes, including laminopathies and related disorders.

BACKGROUND: Segmental progeroid syndromes are a heterogeneous group of rare and often severe genetic disorders that have been studied since the twentieth century. These progeroid syndromes are defined as segmental because only some of the features observed during natural aging are accelerated. METHODS: Since 2015, the Molecular Genetics Laboratory in Marseille La Timone Hospital proposes molecular diagnosis of premature aging syndromes including laminopathies and related disorders upon NGS sequencing of a panel of 82 genes involved in these syndromes. We analyzed the results obtained in 4 years on 66 patients issued from France and abroad. RESULTS: Globally, pathogenic or likely pathogenic variants (ACMG class 5 or 4) were identified in about 1/4 of the cases; among these, 9 pathogenic variants were novel. On the other hand, the diagnostic yield of our panel was over 60% when the patients were addressed upon a nosologically specific clinical suspicion, excepted for connective tissue disorders, for which clinical diagnosis may be more challenging. Prenatal testing was proposed to 3 families. We additionally detected 16 variants of uncertain significance and reclassified 3 of them as benign upon segregation analysis in first degree relatives. CONCLUSIONS: High throughput sequencing using the Laminopathies/ Premature Aging disorders panel allowed molecular diagnosis of rare disorders associated with premature aging features and genetic counseling for families, representing an interesting first-level analysis before whole genome sequencing may be proposed, as a future second step, by the National high throughput sequencing platforms ("Medicine France Genomics 2025" Plan), in families without molecular diagnosis.

Kawasaki disease in adults: Observations in France and literature review.

OBJECTIVE: Kawasaki disease (KD) is a vasculitis that mostly occurs in young children and rarely in adults. We analyzed the characteristics of adult-onset KD (AKD) in France. METHODS: We collected retrospective and prospective data for patients with a diagnosis of KD occurring after the age of 18 years. Cases were obtained via various French medical networks and identified from the international literature. RESULTS: We included 43 patients of AKD at 26 institution from 1992 to 2015, with mean (SD) age 30 (11) years (range 18-68) and sex ratio (M/F) 1.2; 34 patients met the American Heart Association criteria and 9 were incomplete AKD. The median time to diagnosis was 13 days (interquartile range 8-21). The main symptoms were fever (100%), exanthema (98%), changes in the extremities (91%), conjunctivitis (77%), oral cavity changes (89%), cervical adenitis (55%) and cardiac abnormalities (45%). Overall, 35% of patients showed large-vessel vasculitis: coronary vasculitis (26%) and coronary aneurysm (19%). Treatment was mostly intravenous immunoglobulins (79%) and aspirin (81%). Four patients showed myocardial infarction due to coronary vasculitis, but none were treated with IVIg because of late diagnosis. After a median follow-up of 5 months (range 1-117), persistent aneurysm was noted in 9% of cases. Damage was significantly lower with early treatment than late or no treatment (p=0.01). CONCLUSION: Given the high frequency of cardiac involvement and complications in this series of AKD, diagnosis and treatment should not be delayed, and early IVIg treatment seems to improve the outcome.