Neurofibromatosis (NF) refers to a group of three distinct genetic conditions in which tumors grow in the nervous system. The tumors are non-cancerous (benign) and often involve the skin or surrounding bone. Although symptoms are often mild, each condition presents differently. Neurofibromatosis type I (NF1) is typically characterized by café au lait spots, neurofibromas, scoliosis, and headaches. Neurofibromatosis type II (NF2), on the other hand, may present with early-onset hearing loss, cataracts, tinnitus, difficulty walking or maintaining balance, and muscle atrophy. The third type is called schwannomatosis and often presents in early adulthood with widespread pain, numbness, or tingling due to nerve compression.
Congenital insensitivity to pain with anhidrosis (CIPA) is a rare autosomal recessive disorder of the nervous system which prevents the feeling of pain or temperature and prevents a person from sweating. Cognitive disorders are commonly coincidental. CIPA is the fourth type of hereditary sensory and autonomic neuropathy (HSAN), and is also known as HSAN IV.
CADASIL or CADASIL syndrome, involving cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, is the most common form of hereditary stroke disorder, and is thought to be caused by mutations of the NOTCH3 gene on chromosome 19. The disease belongs to a family of disorders called the leukodystrophies. The most common clinical manifestations are migraine headaches and transient ischemic attacks or strokes, which usually occur between 40 and 50 years of age, although MRI is able to detect signs of the disease years prior to clinical manifestation of disease.
Spinocerebellar ataxia (SCA) is a progressive, degenerative, genetic disease with multiple types, each of which could be considered a neurological condition in its own right. An estimated 150,000 people in the United States have a diagnosis of spinocerebellar ataxia at any given time. SCA is hereditary, progressive, degenerative, and often fatal. There is no known effective treatment or cure. SCA can affect anyone of any age. The disease is caused by either a recessive or dominant gene. In many cases people are not aware that they carry a relevant gene until they have children who begin to show signs of having the disorder. Currently, research is being conducted at Universities, such as the University of Minnesota, to elucidate many of the unknown characteristics of the disease.
Pantothenate kinase-associated neurodegeneration (PKAN), formerly called Hallervorden–Spatz syndrome, is a genetic degenerative disease of the brain that can lead to parkinsonism, dystonia, dementia, and ultimately death. Neurodegeneration in PKAN is accompanied by an excess of iron that progressively builds up in the brain.
Aceruloplasminemia is a rare autosomal recessive disorder in which the liver can not synthesize the protein ceruloplasmin properly, which is needed to transport copper around the blood. Copper deficiency in the brain results in neurological problems that generally appear in adulthood and worsen over time.
Peroxisomal disorders represent a class of medical conditions caused by defects in peroxisome functions. This may be due to defects in single enzymes important for peroxisome function or in peroxins, proteins encoded by PEX genes that are critical for normal peroxisome assembly and biogenesis.
Rhizomelic chondrodysplasia punctata is a rare developmental brain disorder characterized by abnormally short arms and legs (rhizomelia), seizures, recurrent respiratory tract infections and congenital cataracts.
Branchio-oto-renal syndrome (BOR) is an autosomal dominant genetic disorder involving the kidneys, ears, and neck. It is also known as Melnick-Fraser syndrome.
Prelamin-A/C, or lamin A/C is a protein that in humans is encoded by the LMNA gene. Lamin A/C belongs to the lamin family of proteins.
Infantile Refsum disease (IRD) is a rare autosomal recessive congenital peroxisomal biogenesis disorder within the Zellweger spectrum. These are disorders of the peroxisomes that are clinically similar to Zellweger syndrome and associated with mutations in the PEX family of genes. IRD is associated with deficient phytanic acid catabolism, as is adult Refsum disease, but they are different disorders that should not be confused.
Multiple sulfatase deficiency (MSD), also known as Austin disease, or mucosulfatidosis, is a very rare autosomal recessive lysosomal storage disease caused by a deficiency in multiple sulfatase enzymes, or in formylglycine-generating enzyme, which activates sulfatases. It is similar to mucopolysaccharidosis.
WD repeat domain phosphoinositide-interacting protein 4 (WIPI-4) is a protein that in humans is encoded by the WDR45 gene. Mutations in this gene cause a distinct form of Neurodegeneration with brain iron accumulation (NBIA) called Beta-propeller protein-associated neurodegeneration (BPAN).
Neuroferritinopathy is a genetic neurodegenerative disorder characterized by the accumulation of iron in the basal ganglia, cerebellum, and motor cortex of the human brain. Symptoms, which are extrapyramidal in nature, progress slowly and generally do not become apparent until adulthood. These symptoms include chorea, dystonia, and cognitive deficits which worsen with age.
Kufor–Rakeb syndrome (KRS) is an autosomal recessive disorder of juvenile onset also known as Parkinson disease-9 (PARK9). It is named after Kufr Rakeb in Irbid, Jordan. Kufor–Rakeb syndrome was first identified in this region in Jordan with a Jordanian couple's 5 children who had rigidity, mask-like face, and bradykinesia. The disease was first described in 1994 by Najim Al-Din et al. The OMIM number is 606693.
Multisystem proteinopathy (MSP) is a dominantly inherited, pleiotropic, degenerative disorder of humans that can affect muscle, bone, and/or the central nervous system. MSP can manifest clinically as classical amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), inclusion body myopathy (IBM), Paget's disease of bone (PDB), or as a combination of these disorders. Historically, several different names have been used to describe MSP, most commonly "inclusion body myopathy with early-onset Paget disease and frontotemporal dementia (IBMPFD)" or "inclusion body myopathy with frontotemporal dementia, Paget's disease of bone, and amyotrophic lateral sclerosis (IBMPFD/ALS)." However, IBMPFD and IBMPFD/ALS are now considered outdated classifications and are more properly referred to as MSP, as the disease is clinically heterogeneous and its phenotypic spectrum extends beyond IBM, PDB, FTD, and ALS to include motor neuron disease, Parkinson's disease features, and ataxia features. Although MSP is rare, growing interest in this syndrome derives from the molecular insights the condition provides into the etiological relationship between common age-related degenerative diseases of muscle, bone, and brain.
NGLY1 deficiency is a very rare genetic disorder caused by biallelic pathogenic variants in NGLY1. It is an autosomal recessive disorder. Errors in deglycosylation are responsible for the symptoms of this condition. Clinically, most affected individuals display developmental delay, lack of tears, elevated liver transaminases and a movement disorder. NGLY1 deficiency is difficult to diagnose, and most individuals have been identified by exome sequencing.
PMM2 deficiency or PMM2-CDG, previously CDG-Ia, is a very rare genetic disorder caused by mutations in PMM2. It is an autosomal recessive disease that is the most common type of congenital disorder of glycosylation or CDG. PMM2-CDG is the most common of a growing family of more than 130 extremely rare inherited metabolic disorders. Only about 800 children and adults have been reported worldwide.
Nasu–Hakola disease also known as polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy is a rare disease characterised by early-onset dementia and multifocal bone cysts. It is caused by autosomal recessive loss of function mutations in either the TREM2 or TYROBP gene that are found most frequently in the Finnish and Japanese populations.
Mitochondrial membrane protein-associated neurodegeneration (MPAN) is a genetic neurodegenerative disease that causes dystonia, parkinsonism, and iron accumulation in the brain. It is caused by mutations to the gene C19orf12, which has unknown function. This was originally discovered as an autosomal recessive disorder, caused by individuals having two mutations to the gene C19orf12, but autosomal dominant disease caused by a single mutation in the same gene has also been rarely described. Due to the common features of neurodegeneration, brain iron accumulation, and movement disorder it is classified as a neurodegeneration with brain iron accumulation (NBIA) disorder and another name for the condition is neurodegeneration with brain iron accumulation 4 (NBIA4).
