Genetic diseases are present throughout the life of an individual, some of which appear very early in life. They result in many chronic conditions that have no cure. Here are the rare genetic diseases and disorders that are seen in human beings.
The rarest genetic disorder known is ribose-5-phosphate isomerase deficiency with a single-known diagnosed case.
Genetic diseases or disorders are caused due to abnormalities in the genetic makeup of an individual. Such abnormalities can be caused by a minuscule, major variation or mutation in single or multiple genes, chromosomal aberrations, and rarely due to mutations in the non-chromosomal DNA of mitochondria. Genetic diseases or disorders may or may not be inheritable. They can be recessive or dominant in nature.
A rare disease in one part of the world may not be rare in another. In the United States, the criteria for rare diseases is defined in the Rare Diseases Act of 2002. It defines such diseases strictly according to its prevalence, specifically “any disease or condition that affects less than 200,000 persons in the United States, or about 1 in 1500.” There are about 6000 known genetic disorders many of which are degenerative, debilitating, and often fatal. In this article, let’s know about some rarer forms of genetic diseases and disorders.
Note.- Know that certain alphabets have been excluded from the index as there are no rare genetic disorders that feature them as their initials.
Symptoms: They include retinal abnormalities and infantile spasms resulting in seizures. Individuals affected by this disease have serious developmental issues.
Treatment: There is no cure for this disorder. Treatment generally involves management of seizures and supporting the affected individuals through the delay in development.
Symptoms: Symptoms include yellowish tinge on the skin and the whites of the eyes, accumulation of cholesterol beneath the skin, itching, etc. Individuals suffering from this disorder also face many heart problems. They have distinguishable facial features — prominent forehead, pointed chin, and deep-set eyes.
Treatment: There is no cure for this syndrome; however, corrective surgery aimed at the functioning of heart, liver, and kidney helps to some extent.
Symptoms: Some of the symptoms of alkaptonuria include darkened skin and pigmented sclera (white part of eye).
Treatment: No specific treatment has been established; however, it has been observed that consuming foods rich in vitamin C helps. It is also advisable to avoid diets rich in tyrosine and phenylalanine.
Symptoms: Indications include childhood obesity, sensorineural hearing loss, and vision impairment. It can also lead to hyperinsulinemia, hypertriglyceridemia, early onset of diabetes 2, and deafness. This syndrome can also cause several life-threatening medical complications involving liver, heart, lungs, etc.
Treatment: There is no cure for this syndrome; however, medication can be provided to cure specific symptoms of the syndrome.
Symptoms: It also results in poor intellectual development of the individual, hearing loss, frequent ear and sinus infections, and short stature. In most cases, the syndrome results due to random gene mutation while in some rare instances, it is inherited as an autosomal dominant trait.
Treatment: There is no cure for this disorder but surgery can, to some extent, cure some of its symptoms.
Symptoms: Symptoms usually appear between 5 to 10 years of age when a normal child suddenly starts having vision problems and seizures. Overtime, the symptoms worsen resulting in loss of motor ability, mental retardation, loss of sight, etc.
Treatment: There is no cure for this condition, and it is generally fatal by the age of 20.
Symptoms: It is characterized by vision impairment, obesity, kidney anomalies, development issues, extra finger and toes, impaired motor skills, etc. This disorder is recessive in nature.
Treatment: There is no cure for the disorder, and usually treatment is concentrated on specific symptoms.
Symptoms: It is characterized by thickened bones resulting in chronic pain. The skull bones also thicken resulting in pressure on the brain, leading to various neurological problems. Individuals suffering from it also complain of increased fatigue, weakness, headache, and muscle spasms.
Treatment: There is no cure for this condition but it can be partially treated. Anti-inflammatory and immunosuppressive agents, like glucocorticosteroids have proved to be helpful in some cases. Alternative therapies, like massage and heat therapy in conjunction with medication are also advisable.
Symptoms: Key symptoms include oddly-shaped head, fused digits, obesity, short stature, and reduced mental ability. 50% of the babies with this disorder have a heart defect which complicates the situation.
Treatment: Treatment generally consists of a number of staged surgeries to correct the malformation of bones in the early stages of life. This condition is similar to Apert Syndrome and Pfeiffer Syndrome.
Symptoms: Key symptoms are clumsiness, fatigue, unsteady posture, muscle cramping, uncontrolled movement, and dementia. Individuals can be affected by this syndrome at any time of their life; however, it is more prevalent in the age group of 40-50 years. Only 60 families are known to be affected by this syndrome in medical literature.
Treatment: There is no cure for this condition. Treatment is generally symptomatic.
Symptoms: Common symptoms of hereditary angioedema include swelling of the arms, legs, eyes, and throat, abdominal pain, and airway blockage.
Treatment: Treatment is usually done by following medication, hormonal treatment, and administration of painkillers.
Symptoms: Indicants include involuntary movements, loss of motor abilities, cognitive difficulties, and emotional problems.
Treatment: There is no cure, but medication can relieve specific symptoms associated with the disorder.
Symptoms: Some key symptoms of this disorder are lack of muscle control, abnormal breathing pattern, jerky eye movement, intellectual disability, and physical deformities, such as cleft lip, extra finger, and toes. The severity of the symptoms varies from individual to individual.
Treatment: There is no cure for the disease but treatment for symptoms, like breathing difficulty can be meted out.
Symptoms: It is characterized by difficulty in breathing, wheezing, chronic cough, sinusitis, bronchitis, and infertility.
Treatment: Treatment for this syndrome is done by following medications, chest physiotherapy, and sometimes, surgical intervention is needed.
Symptoms: This disease is characterized by vomiting, seizures, mental retardation, deafness, and blindness.
Treatment: Bone marrow transplantation has shown to be helpful in some cases of this disease. Recent studies have found out that newborn babies with Krabbe disease can be treated with the help of stem cells from umbilical cord blood storage.
Symptoms: It has severe signs and symptoms including malformed central nervous system, numerous fluid-filled cysts in the kidney, defects in the lungs, liver, polydactyly.
Treatment: Cardiac repair, or neurosurgical intervention for encephalocele may be recommended.
Symptoms: Symptoms include short stature, mental retardation, respiratory diseases, deafness, and blindness.
Treatment: Treatment is done by following enzyme replacement therapy along with regular medical care.
Symptoms: Visible symptoms of this syndrome are unusually broad forehead, bulging eyes, beaked nose, short broad thumbs and toes. In certain cases, webbing of the digits is also seen. Individual suffering from this syndrome also faces hearing loss and dental issues.
Treatment: Staged craniofacial surgeries are usually performed in the early months of life to rectify the deformation in bones.
Symptoms: Key symptoms of progeria are growth problems in the first year of life, wrinkled small face, large head, loss of hair, eyebrows, and eyelashes, poor eyesight, and reduced motor skills. A genetic test for LMNA mutation can confirm if an individual has progeria.
Treatment: There is no cure for this disease. All treatment options offered are generally supportive and symptom-specific.
Symptoms: They include breathing problems, sensory problem, unsteady gait, learning disabilities, seizures, social awkwardness, or unresponsiveness. The symptoms are often misinterpreted with that of autism and cerebral palsy.
Treatment: There is no cure for this syndrome; however, research in this area is ongoing.
The deficiency arises due to a mutation in the enzyme ribose 5-phosphate isomerase, which plays a vital role in the pentose phosphate pathway. With only a single diagnosed case, this disorder is considered to be the rarest. MRI screening showed higly elevated levels of arabitol and ribitol, indicating an inborn error in polyol metabolism. The patient exhibited symptoms like white matter disease and neuropathy of unknown origin. The cause of the condition is yet to be fully understood. There are several theories doing the rounds, but this deficiency is still under study.
Symptoms: Affected babies exhibit muscle weakness, loss of motor skills, suffer hearing loss, paralysis, vision loss, red cherry spots, intellectual disability, and usually survive till the age of 3-4 years.
Treatment: Treatment for this condition is generally supportive.
Symptoms: Common symptoms include skin lesions in the nose and cheek area, periungual fibroma, epileptic seizures, behavioral problems, lung and kidney diseases and mental retardation.
Treatment: Symptoms of epileptic seizures can be treated by surgically removing the tubers that are responsible for epilepsy. Studies are being conducted to find out drug therapies for this disease.
Symptoms: They include feeding issues, constant vomiting, diarrhea, enlarged liver and spleen, poor weight gain, etc.
Treatment: There is no cure for this condition; however, there are treatments that are symptomatic and supportive.
Symptoms: It is characterized by gingival fibromatosis (large gums), absent or underdeveloped nails of terminal phalanges of hand and feet, abnormal nose and ear, and rough facial appearance.
Treatment: Treatment for this syndrome is usually symptomatic and supportive.
Genetic diseases and disorders are a major challenge for medical researchers all over the world. Researches on cloning of genes, gene therapy, and suppression of genes responsible for causing genetic diseases and enzyme replacement are still on to find ways to treat rare genetic diseases and disorders.