Severe obstructive sleep apnea in Loeys-Dietz syndrome successfully treated using continuous positive airway pressure.

Loeys-Dietz syndrome is a recently recognized connective tissue disorder characterized by severe craniofacial and skeletal abnormalities as well as arterial tortuosity with aggressive aneurysm formation. Marfan syndrome, a classic connective tissue disorder, is known to be associated with a risk of obstructive sleep apnea, but sleep-related breathing disorders have not been previously documented in Loeys-Dietz syndrome. The propositus had the prototypic features of Loeys-Dietz syndrome with a de novo mutation in TGFBR2. He developed severe obstructive sleep apnea during his infancy. Continuous positive airway pressure was introduced at age 7 years and provided significant improvement in his nocturnal apnea and sleep apnea-related symptoms, such as enuresis. Marfan syndrome is known to be associated with a high risk of sleep apnea because of its characteristic craniofacial and connective tissue abnormalities. Similarly, the severe craniofacial abnormalities in Loeys-Dietz syndrome may predispose patients to severe obstructive sleep apnea, even at a very young age. Despite the severity of obstructive sleep apnea in the propositus, the administration of continuous positive airway pressure was highly effective in alleviating his symptoms. In summary, severe obstructive sleep apnea was successfully treated using continuous positive airway pressure in a patient with Loeys-Dietz syndrome. Careful evaluation and aggressive intervention for the alleviation of obstructive sleep apnea is warranted in Loeys-Dietz syndrome.

Legius syndrome: A case report.

Legius syndrome is a rare genetic disorder caused by heterozygous germ line loss-of-function SPRED1 mutation. In Japan, a family with Legius syndrome was first described in 2015 by Sakai et al. We described a first solitary case of Legius syndrome identified by next-generation sequencing in Japan. A 37-year-old woman presented with multiple café-au-lait macules and freckles but has no other features of neurofibromatosis type 1 (NF-1). Sequencing results showed the presence of a mutation in exon 2 of SPRED1 c.70C>T, resulting in the protein at position 24 (p.Arg24X). When a dermatological clinician sees an adult patient showing only pigmented lesions and no other specifically diagnostic features of NF-1, it is important to suspect the possibility of Legius syndrome.

The use of next-generation sequencing in molecular diagnosis of neurofibromatosis type 1: a validation study.

AIMS: We assessed the validity of a next-generation sequencing protocol using in-solution hybridization-based enrichment to identify NF1 mutations for the diagnosis of 86 patients with a prototypic genetic syndrome, neurofibromatosis type 1. In addition, other causative genes for classic genetic syndromes were set as the target genes for coverage analysis. RESULTS: The protocol identified 30 nonsense, 19 frameshift, and 8 splice-site mutations, together with 10 nucleotide substitutions that were previously reported to be pathogenic. In the remaining 19 samples, 10 had single-exon or multiple-exon deletions detected by a multiplex ligation-dependent probe amplification method and 3 had missense mutations that were not observed in the normal Japanese SNP database and were predicted to be pathogenic. Coverage analysis of the genes other than the NF1 gene included on the same diagnostic panel indicated that the mean coverage was 115-fold, a sufficient depth for mutation detection. CONCLUSIONS: The overall mutation detection rate using the currently reported method in 86 patients who met the clinical diagnostic criteria was 92.1% (70/76) when 10 patients with large deletions were excluded. The results validate the clinical utility of this next-generation sequencing-based method for the diagnosis of neurofibromatosis type 1. Comparable detection rates can be expected for other genetic syndromes, based on the results of the coverage analysis.