OMIM ID:
Jalili Syndrome
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
Symptoms of photophobia and reduced vision are present in the first years of life. Pendular nystagmus is common. Color vision is defective and is characterized by some as a form of achromatopsia, perhaps better described as dyschromatopsia. Reduced night vision is noted by the end of the first decade of life. OCT reveals reduced foveal and retinal thickness. The macula appears atrophic with pigment mottling and the peripheral retina can resemble retinitis pigmentosa with bone spicule pigment changes. Retinal vessels may be narrow. The ERG shows reduced responses in both photopic and scotopic recordings. This form of rod-cone dystrophy is progressive with central acuity decreasing with age.
Systemic Features
The teeth are abnormally shaped and discolored from birth. The amelogenesis imperfecta consists of hypoplasia and hypomineralization that is present in both deciduous and permanent teeth. Tooth enamel is mineralized only to 50% of normal and is similar to that of dentine.
Genetics
Inheritance
This is an autosomal recessive condition caused by mutations in the CNNM4 gene at 2q11.2.
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.