OMIM ID:
EEM Syndrome
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
Granular pigmentation and a grayish coloration of the retina may be present. The peripheral retina usually appears normal but the posterior pole and macula have pigmentary changes consisting of clumping and geographic atrophy. Fluorescein angiography shows patchy areas of hyperfluorescence. Patients in their 30s have been reported to have normal ERGs in one study. Reduced acuity can be noted in the first decade but progression is slow. Acuity levels in the 20/200 range may be seen in the fourth decade of life.
Systemic Features
Ectodermal dysplasia with ectrodactyly and syndactyly are prominent features of this syndrome. Hypotrichosis of the scalp, eyebrows and eyelashes is often seen. Partial anodontia and diastema are also features. Syndactyly of the toes is present more frequently than found among the fingers.
Genetics
Inheritance
This is an autosomal recessive disorder resulting from mutations in the CDH3 gene (16q22.1).
EEM syndrome is allelic to the Hypotrichosis with Macular Dystrophy syndrome (601553). However, the latter lacks the dental, limb, and digital anomalies as well as the hypotrichosis of eyebrows and eyelashes.
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.