Coloboma, Ptosis, Hypertelorism, and Global Delay
Patient Information
Characteristics
Background and History
This is a recently described syndrome with ocular and severe systemic malformations.
Clinical Correlations
Children are developmentally delayed from birth. They are short in stature, their developmental milestones are delayed, and some have been described as mentally retarded. Physical growth is slow. Their facies are characteristic with a broad nasal bridge, widely-set eyes, low-set (and malformed) ears that are often rotated posteriorly, a short neck and low hair lines. Brain scans reveal severe malformations in some individuals. The iris (colored part of the eye) may have a defect called a coloboma. The eyelids characteristically are ‘droopy’ (ptosis). Little is known about vision in this condition but it was reduced in one child.
Genetics
Inheritance
No gene mutation has been described. Several patients have had microscopic changes in chromosome 2. The family pattern suggests autosomal recessive inheritance.
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.
Diagnosis and Prognosis
The diagnosis might be made by a pediatrician in collaboration with an ophthalmologist. No specific test is available and the diagnosis is based on the physical findings. Nothing is known regarding treatment or prognosis although some patients live into childhood.
Printer Friendly Version: Ctrl/Cmd+P