Amish, Mennonite, and Hutterite
Genetic Disorder Database

Seizures, scoliosis, and macrocephaly syndrome (SSMS)

Disorder
OMIM #: #616682  (Click to access OMIM database)
Disorder: Seizures, scoliosis, and macrocephaly syndrome (SSMS) 
Also known as:  
Clinical
Phenotype: moderate intellectual disability, seizure disorder with onset between 2 and 5 years of age, hypotonia, scoliosis, macrocephaly, coarse facies, bilateral cryptorchidism in males, long hypoplastic philtrum and hypertelorism 
Seen In: Amish
Old Order Mennonite
Old Colony Mennonite
Unknown/Other Mennonite
Hutterite
Remarks:

Testing is available at LHSC.

 

Mutations
1   Old Order Mennonite  
Gene: EXT2
Base Change: T>G, at nucleotide 260
Amino Acid Change: met 87 --> arg
2   Old Order Mennonite  
Gene: EXT2
Base Change: C>T, at nucleotide 283
Amino Acid Change: arg 95 --> cys
Last updated: 2018-04-20 

References
Farhan SM, Wang J, Robinson JF, Prasad AN, Rupar CA, Siu VM; FORGE Canada Consortium, Hegele RA. (2015) Old gene, new phenotype: mutations in heparan sulfate synthesis enzyme, EXT2 leads to seizure and developmental disorder, no exostoses. J Med Genet Oct;52(10):666-75.
PubMed ID: 26246518 

Back