Gillespie syndrome
Encyclopedia
Gillespie syndrome, also called aniridia, cerebellar ataxia and mental deficiency and Gillespie's syndrome II, is a rare genetic disorder
. The disorder is characterized by partial aniridia
(meaning that part of the iris
is missing), ataxia
(motor and coordination problems), and, in most cases, intellectual disability
. It is heterogeneous, inherited in either an autosomal
dominant or autosomal recessive manner. Gillespie syndrome was first described by American ophthalmologist Fredrick Gillespie in 1965.
, and only one copy of the gene is sufficient to cause the disorder, when inherited from a parent who has the disorder.
Autosomal recessive inheritance means the defective gene responsible for the disorder is located on an autosome, but two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry
one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder.
Some forms are associated with PAX6
.
Genetic disorder
A genetic disorder is an illness caused by abnormalities in genes or chromosomes, especially a condition that is present from before birth. Most genetic disorders are quite rare and affect one person in every several thousands or millions....
. The disorder is characterized by partial aniridia
Aniridia
Aniridia is the absence of the iris. Aniridia usually involves both eyes. It can be congenital or caused by a penetrant injury. Isolated aniridia is a congenital disorder which is not limited to a defect in iris development, but is a panocular condition with macular and optic nerve hypoplasia,...
(meaning that part of the iris
Iris (anatomy)
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
is missing), ataxia
Ataxia
Ataxia is a neurological sign and symptom that consists of gross lack of coordination of muscle movements. Ataxia is a non-specific clinical manifestation implying dysfunction of the parts of the nervous system that coordinate movement, such as the cerebellum...
(motor and coordination problems), and, in most cases, intellectual disability
Intellectual disability
Intellectual disability is a broad concept encompassing various intellectual deficits, including mental retardation , deficits too mild to properly qualify as MR, various specific conditions , and problems acquired later in life through acquired brain injuries or neurodegenerative diseases like...
. It is heterogeneous, inherited in either an autosomal
Autosome
An autosome is a chromosome that is not a sex chromosome, or allosome; that is to say, there is an equal number of copies of the chromosome in males and females. For example, in humans, there are 22 pairs of autosomes. In addition to autosomes, there are sex chromosomes, to be specific: X and Y...
dominant or autosomal recessive manner. Gillespie syndrome was first described by American ophthalmologist Fredrick Gillespie in 1965.
Genetics
Gillespie syndrome is a heterogeneous disorder, and can be inherited in either an autosomal dominant or recessive manner. Autosomal dominant inheritance indicates that the defective gene responsible for a disorder is located on an autosomeAutosome
An autosome is a chromosome that is not a sex chromosome, or allosome; that is to say, there is an equal number of copies of the chromosome in males and females. For example, in humans, there are 22 pairs of autosomes. In addition to autosomes, there are sex chromosomes, to be specific: X and Y...
, and only one copy of the gene is sufficient to cause the disorder, when inherited from a parent who has the disorder.
Autosomal recessive inheritance means the defective gene responsible for the disorder is located on an autosome, but two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry
Genetic carrier
A genetic carrier , is a person or other organism that has inherited a genetic trait or mutation, but who does not display that trait or show symptoms of the disease. They are, however, able to pass the gene onto their offspring, who may then express the gene...
one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder.
Some forms are associated with PAX6
PAX6
Paired box protein Pax-6 also known as aniridia type II protein or oculorhombin is a protein that in humans is encoded by the PAX6 gene.- Function :PAX6 is a member of the Pax gene family...
.