Connective tissue dysplasia in five new patients with NF1 microdeletions: further expansion of phenotype and review of the literature

Approximately 5% of patients with neurofibromatosis type 1 (NF1) have deletions of the entire NF1 gene. The phenotype usually includes early onset, large number of neurofibromas, presence of congenital anomalies, cognitive deficiency, and variable dysmorphic features and growth abnormalities. Connective tissue abnormalities are not generally recognised as a part of NF1 microdeletion syndrome, but mitral valve prolapse, joint laxity, and/or soft skin on the palms have been reported in a few patients. We describe clinical findings in six newly diagnosed patients with NF1 microdeletions, five of whom presented with connective tissue abnormalities. A literature review of the clinical findings associated with NF1 microdeletion was also performed. Our report confirms that connective tissue dysplasia is common in patients with NF1 microdeletions. Given the potential for associated cardiac manifestation, screening by echocardiogram may be warranted. Despite the large number (>150) of patients with known NF1 microdeletions, the clinical phenotype remains incompletely defined. Additional reports of patients with NF1 microdeletions, including comprehensive clinical and molecular information, are needed to elucidate possible genotype–phenotype correlation.