Cataracts, Growth Hormone Deficiency, and Skeletal Dysplasia
Patient Information
Characteristics
Background and History
Opacities or loss of transparency of the lens in the eye are called cataracts. They may arise from many causes. Some are congenital (present at birth) and may be inherited either as an isolated finding, or, as in the case of this condition, be part of a more general syndrome. The disorder described here is extremely rare consisting of only a few reported children.
Clinical Correlations
Cataracts are usually diagnosed in infancy or early childhood. Hearing loss (deafness) is noted by 2 years of age. In addition, there is a delay in physical growth during childhood and adults are short in stature. Major developmental milestones such as walking and talking may be delayed. At least some patients have bushy eyebrows, scoliosis (crooked spine), small mouth, and a prominent forehead. The pituitary gland is not fully developed resulting in hormonal deficiencies such as low growth hormone and low levels of cortisol. Some patients have periodic low sugar levels in the blood. Sensations such as touch, pain, and temperature may be reduced.
Brain function and intelligence are normal and individuals can live independently.
Genetics
Inheritance
This condition requires the inheritance of mutations in both copies of a specific gene. Parents with one copy are clinically normal but their children each have a 25% risk of inheriting the duplicate mutations.
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
An ophthalmologist can make the diagnosis of cataracts early but the complex and widespread nature of symptoms requires a team of specialists such as orthopedists, neurologists, pediatricians, and endocrinologists.
Longevity is probably not impacted and general functioning can be normal with hormone replacement therapy. Visually significant cataracts can be surgically removed and corrective action for abnormal spinal curvature may be needed.
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