Patients that present with CARASIL usually experience neurological abnormalities by their 20s or 30s and strokes upon reaching their 40s. About 50% of affected patients present with stroke, and most strokes experienced by patients are lacunar infarcts. Many patients experience some form of mood changes, personality disorders, and or dementia. Alopecia, also known as hair loss, usually presents beginning in adolescence. The presence of spondylosis deformans and the onset of low back pain via the breakdown of intervertebral discs is also usually present. CARASIL is a degenerative disease, and most patients live only 10 years past symptom onset.

Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL), is an inherited disease with symptoms of stroke, hair loss, and low back pain. The disease is rare and has only been diagnosed in about 50 patients, mostly of Japanese descent but few of Chinese and Spanish descent. There is currently no cure for CARASIL.

CADASIL may start with attacks of migraine with aura or subcortical transient ischemic attacks or strokes, or mood disorders between 35 and 55 years of age. The disease progresses to subcortical dementia associated with pseudobulbar palsy and urinary incontinence.

Ischemic strokes are the most frequent presentation of CADASIL, with approximately 85% of symptomatic individuals developing transient ischemic attacks or stroke(s). The mean age of onset of ischemic episodes is approximately 46 years (range 30–70). A classic lacunar syndrome occurs in at least two-thirds of affected patients while hemispheric strokes are much less common. It is worthy of note that ischemic strokes typically occur in the absence of traditional cardiovascular risk factors. Recurrent silent strokes, with or without clinical strokes, often lead to cognitive decline and overt subcortical dementia. A case of CADASIL presenting as schizophreniform organic psychosis has been reported.

Onset usually occurs in childhood, however some adult cases have been found. Generally, physicians look for the symptoms in children. Symptoms include cerebellar ataxia, spasticity, optic atrophy, epilepsy, loss of motor functions, irritability, vomiting, coma, and even fever has been tied to VWM. The neurological disorders and symptoms which occur with VWM are not specific to countries; they are the same all over the world. Neurological abnormalities may not always be present in those who experience onset as adults. Symptoms generally appear in young children or infants who were previously developing fairly normally.

Persons with HDLS can suffer from tremors, decreased body movement, unsteadiness (Parkinsonism, muscles on one side of the body in constant contraction (spastic hemiparesis), impairment in motor and sensory function in the lower extremities (paraparesis), paralysis resulting in partial or total loss of all extremities and torso (tetraparesis), and the lack of voluntary coordination of muscle movements (ataxia).

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 "Notch 3" 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.

With symptoms of personality changes, behavioral changes, dementia, depression, and epilepsy, HDLS has been commonly misdiagnosed for a number of other diseases. Dementia or frontotemporal behavioral changes, for example, have commonly steered some clinicians to mistakenly consider diagnoses such as Alzheimer’s disease, frontotemporal dementia or atypical Parkinsonism. The presence of white matter changes has led to misdiagnosis of multiple sclerosis. HDLS commonly manifests with neuropsychiatric symptoms, progressing to dementia, and after a few years shows motor dysfunction. Eventually patients become wheelchair-bound or bedridden.

White matter degeneration is associated with and makes differential diagnoses out of other adult onset leukodystrophies such as metachromatic leukodystrophy (MLD), Krabbe disease (globoid cell leukodystrophy), and X-linked adrenoleukodystrophy (X-ADL).

Leukoencephalopathy with vanishing white matter (VWM disease) is an autosomal recessive neurological disease. The cause of the disease are mutations in any of the 5 genes encoding subunits of the translation initiation factor EIF-2B: EIF2B1, EIF2B2, EIF2B3, EIF2B4, or EIF2B5. The disease belongs to a family of conditions called the Leukodystrophies.

Megalencephalic leukoencephalopathy with subcortical cysts (MLC, or Van der Knaap disease) is a form of hereditary CNS demyelinating disease. It belongs to a group of disorders called leukodystrophies.

It is associated with MLC1. Van der Knaap disease is named after Dutch neurologist Marjo van der Knaap.

Like other mitochrondrial diseases, "MNGIE is a multisystem disorder". MNGIE primarily affects the gastrointestinal and neurological systems. Gastrointestinal symptoms may include gastrointestinal dysmotility, due to inefficient peristalsis, which may result in pseudo-obstruction and cause malabsorption of nutrients. Additionally, gastrointestinal symptoms such as borborygmi, early satiety, diarrhea, constipation, gastroparesis, nausea, vomiting, weight loss, and diverticulitis may be present in MNGIE patients. Neurological symptoms may include diffuse leukoencephalopathy, peripheral neuropathy, and myopathy. Ocular symptoms may include retinal degeneration, ophthalmoplegia, and ptosis. Those with MNGIE are often thin and experience continuous weight loss. The characteristic thinness of MNGIE patients is caused by multiple factors including inadequate caloric intake due to gastrointestinal symptoms and discomfort, malabsorption of food from bacterial overgrowth due to decreased motility, as well as an increased metabolic demand due to inefficient production of ATP by the mitochondria.

Giant axonal neuropathy usually appears in infancy or early childhood, and is progressive. Early signs of the disorder often present in the peripheral nervous system, causing individuals with this disorder to have problems walking. Later, normal sensation, coordination, strength, and reflexes become affected. Hearing or vision problems may also occur. Abnormally kinky hair is characteristic of giant axonal neuropathy, appearing in almost all cases. As the disorder progresses, central nervous system becomes involved, which may cause a gradual decline in mental function, loss of control of body movement, and seizures.

Non-progressive congenital ataxia (NPCA) is a non-progressive form of cerebellar ataxia which can occur with or without cerebellar hypoplasia.

Onset : Early childhood

Progression: Chronic progressive

Clinical: Cerebellar ataxia plus syndrome / Optic Atrophy Plus Syndrome

Ocular: Optic atrophy, nystagmus, scotoma, and bilateral retrobulbar neuritis.

Other: Mental retardation, myoclonic epilepsy, spasticity, and posterior column sensory loss. Tremor in some cases.

Musculoskeletal

Contractures, lower limbs, Achilles tendon contractures, Hamstring contractures, Adductor longus contractures

Systemic

Hypogonadotrophic hypogonadism.

Some specific symptoms vary from one type of leukodystrophy to the next but the vast majority of symptoms are shared as the causes for the disease generally have the same effects. Symptoms are dependent on the age of onset, which is predominantly in infancy and early childhood, although the exact time of onset may be difficult to determine. Hyperirritability and hypersensitivity to the environment are common, as well as some tell-tale physical signs including muscle rigidity and a backwards-bent head. Botox therapy is often used to treat patients with spasticity. Juvenile and adult onsets display similar symptoms including a decrease or loss in hearing and vision. While children do experience optic and auditory degeneration, the course of the disease is usually too rapid, causing death relatively quickly, whereas adults may live with these conditions for many years. In children, spastic activity often precedes progressive ataxia and rapid cognitive deterioration which has been described as mental retardation. Epilepsy is commonplace for patients of all ages. More progressed patients show weakness in deglutition, leading to spastic coughing fits due to inhaled saliva. Classic symptomatic progression of juvenile x-linked adrenoleukodystrophy is shown in the 1992 film, "Lorenzo's Oil".

Course and timetable are dependent on the age of onset with infants showing a lifespan of 2–8 years, juveniles 2–10 years and adults typically 10+ years. Adults typically see an extended period of stability followed by a decline to a vegetative state and death. While treatments do exist, most are in the experimental phase and can only promise a halt in the progression of symptoms, although some gene therapies have shown some symptomatic improvement. The debilitating course of the disease has led to numerous philosophical and ethical arguments over experimental clinical trials, patients’ rights and physician-assisted suicide.

An inherited disorder associated with the deposition of a steroid known as cholestanol in the brain and other tissues and with elevated levels of cholesterol in plasma but with normal total cholesterol level; it is characterized by progressive cerebellar ataxia beginning after puberty and by juvenile cataracts, juvenile or infantile onset chronic diarrhea, childhood neurological deficit, and tendineous or tuberous xanthomas.

Neuroimaging like MRI is important. However, there was considerable intrafamilial variability regarding neuroimaging, with some individuals showing normal MRI findings. Early individual prognosis of such autosomal recessive cerebellar ataxias is not possible from early developmental milestones, neurological signs, or neuroimaging.

Behr syndrome is characterized by the association of early-onset optic atrophy with spinocerebellar degeneration resulting in ataxia, pyramidal signs, peripheral neuropathy and developmental delay.

Although it is an autosomal recessive disorder, heterozygotes may still manifest much attenuated symptoms. Autosomal dominant inheritance also being reported in a family. Recently a variant of OPA1 mutation with phenotypic presentation like Behr syndrome is also described. Some reported cases have been found to carry mutations in the OPA1, OPA3 or C12ORF65 genes which are known causes of pure optic atrophy or optic atrophy complicated by movement disorder.

A hereditary CNS demyelinating disease is a demyelinating central nervous system disease that is primarily due to an inherited genetic condition. (This is in contrast to autoimmune demyelinating conditions, such as multiple sclerosis, or conditions such as central pontine myelinolysis that are associated with acute acquired insult.)

Examples include:

- Alexander disease

- Canavan disease

- Krabbe disease

- leukoencephalopathy with vanishing white matter

- megalencephalic leukoencephalopathy with subcortical cysts

- metachromatic leukodystrophy

- X-linked adrenoleukodystrophy

Giant axonal neuropathy is a rare, autosomal recessive neurological disorder that causes disorganization of neurofilaments. Neurofilaments form a structural framework that helps to define the shape and size of neurons and are essential for normal nerve function.

Specific types of leukodystrophies include the following with their respective ICD-10 codes when available:

- (E71.3) Adrenomyeloneuropathy

- (E75.2) Alexander disease

- (E75.5) Cerebrotendineous xanthomatosis

- Hereditary CNS demyelinating disease

- (E75.2) Krabbe disease

- (E75.2) Metachromatic leukodystrophy

- (E75.2) Pelizaeus–Merzbacher disease

- (E75.2) Canavan disease

- (G93.49) Leukoencephalopathy with vanishing white matter

- (E71.3) Adrenoleukodystrophy

- (G60.1) Refsum disease

Mitochondrial neurogastrointestinal encephalopathy syndrome (MNGIE) is a rare autosomal recessive mitochondrial disease. It has been previously referred to as polyneuropathy, ophthalmoplegia, leukoencephalopathy, and POLIP syndrome. The disease presents in childhood, but often goes unnoticed for decades. Unlike typical mitochondrial diseases caused by mitochondrial DNA (mtDNA) mutations, MNGIE is caused by mutations in the TYMP gene, which encodes the enzyme thymidine phosphorylase. Mutations in this gene result in impaired mitochondrial function, leading to intestinal symptoms as well as neuro-ophthalmologic abnormalities. "A secondary form of MNGIE, called MNGIE without leukoencephalopathy, can be caused by mutations in the POLG gene".

The signs/symptoms of this condition are consistent with the following:

- Intellectual disability,

- Muscular hypotonia

- Encephalitis

- Seizures

- Aphasia

The symptoms have been known to include apathy, dementia, Parkinsonism, agitation, urinary incontinence, and pseudobulbar palsy, among many other neuropsychiatric symptoms.

Microscopically, extensive hemispheric demyelination and the degeneration of basal ganglia are observed.

2-hydroxyglutaric aciduria is an organic aciduria, and because of the stereoisomeric property of 2-hydroxyglutarate different variants of this disorder are distinguished:

Cerebrotendineous xanthomatosis or cerebrotendinous xanthomatosis (CTX), also called cerebral cholesterosis, is an autosomal recessive form of xanthomatosis. It falls within a group of genetic disorders called the leukodystrophies.