Blau Syndrome Associated with Nucleotide-binding Oligomerization Domain Containing 2 Mutation in a Baby from Malaysia

Blau syndrome (BS) is a very rare autosomal dominant juvenile inflammatory disorder caused by mutation in nucleotide-binding oligomerization domain containing 2 (NOD2). Usually, dermatitis is the first symptom that appears in the 1st year of life. About 220 BS cases with confirmed NOD2 mutation have been reported. However, the rarity and lack of awareness of the disease, especially in the regions where genetic tests are very limited, often result in late diagnosis and misdiagnosis. Here, we report a de novo BS case from Malaysia, which may be the first report from southeast Asia. PCR and DNA sequencing of peripheral blood mononuclear cells were performed to screen the entire coding region of NOD2 gene. A heterozygous c.1000C>T transition in exon 4, p. R334W, of the NOD2 gene was identified in the patient. This report further reaffirms the ubiquitousness of the disease and recurrency of p. R334W mutation.