X-linked cone-rod dystrophy, type 1 | |
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Other names | CORDX1, CORD1, Cone-rod dystrophy X-linked 1. [1] |
Specialty | Medical genetics, optometry, ophthalmology |
Usual onset | Early infancy |
Duration | Lifelong |
Causes | Genetic mutation |
Prevention | none |
Prognosis | Medium |
Frequency | rare |
Deaths | - |
X-linked cone-rod dystrophy, type 1 is a rare progressive genetic disorder of the vision which is characterized by progressive myopia, photophobia, abnormal color perception, lowered photopic electroretinigraphic response, and macular retinal pigment epithelium granularity. The severity of the symptoms is variable. Peripheral vision is unaffected in most of the cases. [2] It is one of the three types of X-linked cone-rod dystrophy. [3]
This condition is linked to mutations (c.2383G > T, p.E795X) in the RPGR gene, located in the Xp11.4 region of the X chromosome, and it is inherited in an X-linked dominant manner with full penetrance, because of this, it mostly affects males. [4] [3] [5] [6]
Prevalence is unknown, although usual cone-rod dystrophy has a prevalence of around 1-9 out of 40,000-100,000 live births. [7] [8]
Retinitis pigmentosa (RP) is a genetic disorder of the eyes that causes loss of vision. Symptoms include trouble seeing at night and decreasing peripheral vision. As peripheral vision worsens, people may experience "tunnel vision". Complete blindness is uncommon. Onset of symptoms is generally gradual and often begins in childhood.
Limb–girdle muscular dystrophy (LGMD) is a genetically heterogeneous group of rare muscular dystrophies that share a set of clinical characteristics. It is characterised by progressive muscle wasting which affects predominantly hip and shoulder muscles. LGMD usually has an autosomal pattern of inheritance. It currently has no known cure or treatment.
Monochromacy is the ability of organisms or machines to perceive only light intensity, without respect to spectral composition (color). Organisms with monochromacy are called monochromats.
Duchenne muscular dystrophy (DMD) is a severe type of muscular dystrophy that primarily affects boys. Muscle weakness usually begins around the age of four, and worsens quickly. Muscle loss typically occurs first in the thighs and pelvis followed by the arms. This can result in trouble standing up. Most are unable to walk by the age of 12. Affected muscles may look larger due to increased fat content. Scoliosis is also common. Some may have intellectual disability. Females with a single copy of the defective gene may show mild symptoms.
The heritability of autism is the proportion of differences in expression of autism that can be explained by genetic variation; if the heritability of a condition is high, then the condition is considered to be primarily genetic. Autism has a strong genetic basis, although the genetics of autism are complex and it is unclear whether autism spectrum disorder (ASD) is explained more by multigene interactions or by rare mutations with major effects.
The photoreceptor cell-specific nuclear receptor (PNR), also known as NR2E3, is a protein that in humans is encoded by the NR2E3 gene. PNR is a member of the nuclear receptor super family of intracellular transcription factors.
X-linked retinitis pigmentosa GTPase regulator is a GTPase-binding protein that in humans is encoded by the RPGR gene. The gene is located on the X-chromosome and is commonly associated with X-linked retinitis pigmentosa (XLRP). In photoreceptor cells, RPGR is localized in the connecting cilium which connects the protein-synthesizing inner segment to the photosensitive outer segment and is involved in the modulation of cargo trafficked between the two segments.
ATP-binding cassette, sub-family A (ABC1), member 4, also known as ABCA4 or ABCR, is a protein which in humans is encoded by the ABCA4 gene.
Peripherin-2 is a protein, that in humans is encoded by the PRPH2 gene. Peripherin-2 is found in the rod and cone cells of the retina of the eye. Defects in this protein result in one form of retinitis pigmentosa, an incurable blindness.
Cav1.4 also known as the calcium channel, voltage-dependent, L type, alpha 1F subunit (CACNA1F), is a human gene.
Cone-rod homeobox protein is a protein that in humans is encoded by the CRX gene.
Protein XRP2 is a protein that in humans is encoded by the RP2 gene.
Cyclic nucleotide-gated cation channel alpha-3 is a protein that in humans is encoded by the CNGA3 gene.
Guanylyl cyclase-activating protein 1 is an enzyme that in humans is encoded by the GUCA1A gene.
Elongation of very long chain fatty acids protein 4 is a protein that in humans is encoded by the ELOVL4 gene.
Cyclic nucleotide gated channel beta 3, also known as CNGB3, is a human gene encoding an ion channel protein.
Oxygen-regulated protein 1 also known as retinitis pigmentosa 1 protein (RP1) is a protein that in humans is encoded by the RP1 gene.
Retinol dehydrogenase 12 is an enzyme that in humans is encoded by the RDH12 gene.
Jalili syndrome is a genetic disorder characterized by the combination of cone-rod dystrophy of the retina and amelogenesis imperfecta. It was characterized in 1988 by Dr. I. K. Jalili and Dr. N. J. D. Smith, following the examination of 29 members of an inbred, Arab family living within the Gaza Strip.
Occult macular dystrophy (OMD) is a rare inherited degradation of the retina, characterized by progressive loss of function in the most sensitive part of the central retina (macula), the location of the highest concentration of light-sensitive cells (photoreceptors) but presenting no visible abnormality. "Occult" refers to the degradation in the fundus being difficult to discern. The disorder is called "dystrophy" instead of "degradation" to distinguish its genetic origin from other causes, such as age. OMD was first reported by Y. Miyake et al. in 1989.