Singleton-Merten Syndrome 2

Clinical Characteristics
Ocular Features: 

Glaucoma has been diagnosed in multiple members of 4 a generation Korean family in which various features of this disorder were found.  The glaucoma is likely congenital in origin as it has been diagnosed in patients as young as 3 years of age

Systemic Features: 

Calcification of the aorta and other large vessels may be identified in childhood.  The aortic valve and coronary arteries may become calcified in young adults as well, sometimes resulting in aortic stenosis.  Arthritis resulting from calcified tendons as well as ligaments of the interphalangeal and metacarpophalangeal joints may occur in young adults.  The skin is often scaly and dry with psoriatic lesions.  The terminal tufts of the digits have evidence of erosion.

Genetics

Heterozygous mutations in the DDX58 gene (9p21.1) have been associated with this disorder.  Some of the clinical features overlap those of Singleton-Merten Syndrome 2 (182250) but this is a unique disorder caused by a different mutation (IFIH1).

Treatment
Treatment Options: 

Glaucoma should be treated with pressure-lowering drugs and surgery.  It may be possible to decalcify cardiovascular structures in select patients and to perform valve replacement.

References
Article Title: 

Mutations in DDX58, which encodes RIG-I, cause atypical Singleton-Merten syndrome

Jang MA, Kim EK, Now H, Nguyen NT, Kim WJ, Yoo JY, Lee J, Jeong YM, Kim CH, Kim OH, Sohn S, Nam SH, Hong Y, Lee YS, Chang SA, Jang SY, Kim JW, Lee MS, Lim SY, Sung KS, Park KT, Kim BJ, Lee JH, Kim DK, Kee C, Ki CS. Mutations in DDX58, which encodes RIG-I, cause atypical Singleton-Merten syndrome. Am J Hum Genet. 2015 Feb 5;96(2):266-74.

PubMed ID: 
25620203

References

Jang MA, Kim EK, Now H, Nguyen NT, Kim WJ, Yoo JY, Lee J, Jeong YM, Kim CH, Kim OH, Sohn S, Nam SH, Hong Y, Lee YS, Chang SA, Jang SY, Kim JW, Lee MS, Lim SY, Sung KS, Park KT, Kim BJ, Lee JH, Kim DK, Kee C, Ki CS. Mutations in DDX58, which encodes RIG-I, cause atypical Singleton-Merten syndrome. Am J Hum Genet. 2015 Feb 5;96(2):266-74.

PubMedID: 25620203