Al Kaissi Syndrome
Patient Information
Characteristics
Background and History
This is a severe developmental disorder so far found in 5 unrelated families of Tunisian, Algerian, Saudi Arabian, and Turkish descent.
Clinical Correlations
Children have severe growth retardation starting before birth. Muscle tone is decreased (hypotonia). Developmental milestones such as sitting, speech, and walking are delayed. Intellectual disability may be severe. The face and head exhibit a number of unusual morphologic features. The face appears triangular, the chin is small, and the forehead is narrow while the ears are low-set and posteriorly rotated. The hands are usually small and have deep creases in the palm. The bridge of the nose is depressed while the nasal tip is broad. The eyes appear abnormally wide apart. The eyelids often droop and the eyelid openings slant downward.
A brain MRI may be normal although some patients have underdevelopment of a structure called the corpus callosum which connects the two sides of the brain. There may be anomalies of the upper spine.
Genetics
Inheritance
This condition results from changes (mutations) in both members of a specific gene. Parents may carry a single mutation and are clinically normal. However, when both mother and father carry the mutation they confer a 25% risk to each of their offspring for this condition.
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
Most of the physical features are not unique to this syndrome and the diagnosis requires a gene study. Ophthalmologists, neurologists, and pediatricians are likely to cooperate on the evaluation and care of Al Kaissi patients.
No treatment for this disorder is known and there is no information regarding longevity.
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