All types of Griscelli syndrome have distinctive skin and hair coloring.

Type 1 is associated with eurological abnormalities. These include delayed development, intellectual disability, seizures, hypotonia and eye abnormalities.

Type 2 - unlike type 1 - is not associated primary neurological disease but is associated with an uncontrolled T lymphocyte expansion and macrophage activation syndrome. It is often associated with the hemophagocytic syndrome. This latter condition may be fatal in the absence of bone marrow transplantation.

Persons with type 3 have the typical light skin and hair coloring but are otherwise normal.

Though not always present, the cardinal characteristics of this multi-system disorder include: cardiomyopathy (dilated or hypertrophic, possibly with left ventricular noncompaction and/or endocardial fibroelastosis), neutropenia (chronic, cyclic, or intermittent), underdeveloped skeletal musculature and muscle weakness, growth delay, exercise intolerance, cardiolipin abnormalities, and 3-methylglutaconic aciduria.

It can be associated with stillbirth.

Barth syndrome is manifested in a variety of ways at birth. A majority of BTHS patients are hypotonic at birth, show signs of cardiomyopathy within the first few months of life, and experience a deceleration in growth in the first year, despite adequate nutrition. As patients progress into childhood, their height and weight lag significantly behind other children. While most patients express normal intelligence, a high proportion of BTHS patients also express mild or moderate learning disabilities. Physical activity is also hindered due to diminished muscular development and muscular hypotonia. Many of these disorders are resolved after puberty. Growth accelerates during puberty, and many patients reach a normal adult height.

Cardiomyopathy is one of the more severe manifestations of BTHS. The myocardium is dilated, reducing the systolic pump of the ventricles. For this reason, most BTHS patients have left myocardial thickening (hypertrophy). While cardiomyopathy can be life-threatening, it is commonly resolved or substantially improved in BTHS patients after puberty.

Neutropenia is another deadly manifestation of BTHS. Neutropenia is a granulocyte disorder that results in a low production of neutrophils, the body’s primary defenders against bacterial infections. Surprisingly, however, BTHS patients have relatively fewer bacterial infections than other patients with neutropenia.

Facial features found in this syndrome include

- dolichocephaly

- hypertelorism

- ptosis

- microretrognathia

- high arched palate

- long flat philtrum

- low set ears

Non facial features of this syndrome include

- hyperextensibility

- hypotonia

- lateral meningoceles

The lateral meningocoles are a common finding in this syndrome. They may be associated with neurological abnormalities and result in bladder dysfunction and neuropathy.

This autosomal dominant disorder is characterized by a number of health defects including Hirschsprung's disease, intellectual disability, epilepsy, delayed growth and motor development, congenital heart disease, genitourinary anomalies and absence of the corpus callosum. However, Hirschsprung's disease is not present in all infants with Mowat–Wilson syndrome and therefore it is not a required diagnostic criterion. Distinctive physical features include microcephaly, narrow chin, cupped ears with uplifted lobes with central depression, deep and widely set eyes, open mouth, wide nasal bridge and a shortened philtrum.

Many of the physical features associated with the disorder are congenital. Characteristic craniofacial abnormalities typically include a long, narrow head that is disproportionate to the body size, a broad and prominent forehead, and a triangular-shaped face with a hypoplastic midface, pointed chin, prominent mouth, fleshy tipped upturned nose, large ears, and full lips. The teeth may be abnormally crowded together in some affected individuals.

Approximately 100 cases have been described in the literature to date.

The facial features are characteristic and include

- Deep set eyes

- Strabismus

- Myopia

- Marked nasal root

- Broad and/or beaked nasal bridge

- Prominent Cupid's bow

- Everted lower lip

- Tented upper lip

- Large mouth

- Widely spaced teeth

- Wide and shallow palate

- Ears with thick and overfolded helix

Most have a smiling appearance.

Intellectual disability is severe. Language is absent or limited to only a few words. Stereotypic movements particularly of the arms, wrists and fingers is almost universal. Hypotonia is common (75%) as is an unsteady gait. All have delayed walking. Other features include a single (simian) palmar crease, long, slender fingers, flat feet and cryptorchidism (in males). Finger clubbing and the presence of fetal pads is common. Hyperventilation occurs in over half and is frequently followed by apnea and cyanosis. During these episodes aerophagia may occur. Constipation is common. Microcephaly and seizures may occur. Hypopigmented skin macules have occasionally been reported.

Skeletal anomalies aren't present at birth but develop in the individual and include delayed bone maturation, slender long tubular bones, and tall vertebral bodies. Joint hyper-mobility and increased risk of hip dislocation has been presented in individuals. Abnormal spinal curvature, either kyhoscholiosis or hyperlordosis, causing back pain can also be experienced from this disorder.

The characteristic symptom of Costeff syndrome is the onset of progressively worsening eyesight caused by degeneration of the optic nerve (optic atrophy) within the first few years of childhood, with the majority of affected individuals also developing motor disabilities later in childhood. Occasionally, people with Costeff syndrome may also experience mild cognitive disability.

It is type of 3-methylglutaconic aciduria, the hallmark of which is an increased level in the urinary concentrations of 3-methylglutaconic acid and 3-methylglutaric acid; this can allow diagnosis as early as at one year of age.

Those with Costeff syndrome typically experience the first symptoms of visual deterioration within the first few years of childhood, which manifests as the onset of progressively decreasing visual acuity. This decrease tends to continue with age, even after childhood.

The majority of people with Costeff syndrome develop movement problems and motor disabilities later in childhood, the two most significant of which are choreoathetosis and spasticity. The former causes involuntary erratic, jerky, and twisting movements (see chorea and athetosis), whereas the latter causes twitches and spastic tendencies.

These two symptoms are often severe enough to seriously disable an individual; among 36 people with Costeff syndrome, 17 experienced major motor disability as a result of choreoathetosis, and 12 experienced spasticity-related symptoms severe enough to do the same.

Ataxia (loss of muscle coordination) and speech impairment caused by dysarthria also occur in roughly 50% of cases, but are rarely seriously disabling.

Some individuals with Costeff disease also display mild cognitive impairment, though such cases are relatively infrequent.

Griscelli syndrome type 2 (also known as "partial albinism with immunodeficiency") is a rare autosomal recessive syndrome characterized by variable pigmentary dilution, hair with silvery metallic sheen, frequent pyogenic infections, neutropenia, and thrombocytopenia.

Galloway Mowat syndrome is a very rare autosomal recessive genetic disorder, consisting of a variety of features including hiatal hernia, microcephaly and nephrotic syndrome.

One Finnish study which followed 25 cases from 18 families found that half the infants died within 3 days of birth and the other half died before 4 months of age.

Barth syndrome (BTHS), also known as 3-Methylglutaconic aciduria type II, is an X-linked genetic disorder. The disorder, which affects multiple body systems, is diagnosed almost exclusively in males. It is named after Dutch pediatric neurologist Masa Barth.

The lateral meningocele syndrome is a very rare skeletal disorder with facial anomalies, hypotonia and meningocele-related neurologic dysfunction.

Mowat–Wilson syndrome is a rare genetic disorder that was clinically delineated by Dr. D. R. Mowat and Dr. M. J. Wilson in 1998.

Acrocallosal syndrome (also known as ACLS) is a rare autosomal recessive syndrome characterized by corpus callosum agenesis, polydactyly, multiple dysmorphic features, motor and mental retardation, and other symptoms. The syndrome was first described by Albert Schinzel in 1979.

It is associated with "GLI3".

The brain is abnormally smooth, with fewer folds and grooves. The face, especially in children, has distinct characteristics including a short nose with upturned nares, thickened upper lip with a thin vermilion upper border, frontal bossing, small jaw, low-set posteriorily rotated ears, sunken appearance in the middle of the face, widely spaced eyes, and hypertelorism. The forehead is prominent with bitemporal hollowing.

Characteristics that are not visual include mental retardation, pre- and postnatal growth retardation, epilepsy, and reduced lifespan.

Failure to thrive, feeding difficulties, seizures and decreased spontaneous activity are often seen. Death usually occurs in infancy and childhood.

Multiple abnormalities of the brain, kidneys, and gastrointestinal tract (the stomach and intestines) may occur.

GRACILE syndrome is a very rare autosomal recessive genetic disorder, one of the Finnish heritage diseases. It is caused by mutation in BCS1L gene that occurs in at least 1 out of 47,000 live births in Finnish people.

GRACILE is an acronym for growth retardation, amino aciduria (amino acids in the urine), cholestasis, iron overload, lactic acidosis, and early death. Other names for this syndrome include Finnish lethal neonatal metabolic syndrome (FLNMS); lactic acidosis, Finnish, with hepatic hemosiderosis; and Fellman syndrome.

Differential diagnosis includes Angelman syndrome, Mowat–Wilson syndrome and Rett syndrome.

Most of the signs and symptoms of the Joubert syndrome appear very early in infancy with most children showing delays in gross motor milestones. Although other signs and symptoms vary widely from individual to individual, they generally fall under the hallmark of cerebellum involvement or in this case, lack thereof. Consequently, the most common features include ataxia (lack of muscle control), hyperpnea (abnormal breathing patterns), sleep apnea, abnormal eye and tongue movements, and hypotonia in early childhood. Other malformations such as polydactyly (extra fingers and toes), cleft lip or palate, tongue abnormalities, and seizures may also occur. Developmental delays, including cognitive, are always present to some degree.

Those suffering from this syndrome often exhibit specific facial features such as a broad forehead, arched eyebrows, ptosis (droopy eyelids), hypertelorism (widely spaced eyes), low-set ears and a triangle shaped mouth. Additionally, this disease can include a broad range of other abnormalities to other organ systems such as retinal dystrophy, kidney diseases, liver diseases, skeletal deformities and endocrine (hormonal) problems.

It is characterized by developmental defects including cryptophthalmos (where the eyelids fail to separate in each eye), and malformations in the genitals (such as micropenis, cryptorchidism or clitoromegaly). Congenital malformations of the nose, ears, larynx and renal system, as well as mental retardation, manifest occasionally. Syndactyly (fused fingers or toes) has also been noted.

Costeff syndrome, or 3-methylglutaconic aciduria type III, is a genetic disorder caused by mutations in the "OPA3" gene. It is typically associated with the onset of visual deterioration (optic atrophy) in early childhood followed by the development of movement problems and motor disability in later childhood, occasionally along with mild cases of cognitive deficiency. The disorder is named after Hanan Costeff, the doctor who first described the syndrome in 1989.

Miller–Dieker syndrome (abbreviated MDS), Miller–Dieker lissencephaly syndrome (MDLS), and chromosome 17p13.3 deletion syndrome is a micro deletion syndrome characterized by congenital malformations. Congenital malformations are physical defects detectable in an infant at birth which can involve many different parts of the body including the brain, hearts, lungs, liver, bones, or intestinal tract.

MDS is a contiguous gene syndrome - a disorder due to the deletion of multiple gene loci adjacent to one another. The disorder arises from the deletion of part of the small arm of chromosome 17p (which includes both the "LIS1" and "14-3-3 epsilon" genes), leading to partial monosomy. There may be unbalanced translocations (i.e. 17q:17p or 12q:17p), or the presence of a ring chromosome 17.

This syndrome should not be confused with Miller syndrome, an unrelated rare genetic disorder, or Miller Fisher syndrome, a form of Guillain–Barré syndrome.

The specific and familial association of BIFE and PKC defines a novel clinical entity : the infantile convulsions and choreoathetosis syndrome. The first observation was made in four families where children were affected with nonfebrile convulsions at age 3–12 months.Partial epileptic seizures started with a psychomotor arrest and a deviation of the head and eyes to one side, followed inconstantly by unilateral jerks.In some cases, seizures generalized secondarily. None of the interictal electroencephalograms showed epileptiform abnormalities, and magnetic-resonance imaging were normal. These convulsions had a favorable outcome. At 5–8 years of age affected children developed abnormal movements. They presented with twisting movements of the hands of a reptilian type when stressed or embarrassed. They also developed jerky movements of the legs after running. Initially, abnormal movements were intermediate in speed between quick and slow, typical of paroxysmal choreoathetosis. Combinations of abnormal movements involving the arms, legs, trunk and occasionally the head were observed. The attacks lasted only a few minutes, occurring with a frequency of 5-30 episodes per day and were not accompanied by unconsciousness. In all patients, abnormal movements disappeared at 25–30 years of age without any treatment. Since the first report similar clinical presentations have been published which confirm the specificity of the ICCA syndrome.

Acrocallosal syndrome (ACLS, ACS, Schinzel-Type, Hallux-duplication) is a rare, heterogeneous [3] autosomal recessive disorder first discovered by Albert Schinzel (1979) in a 3-year-old boy . To inherit ACLS, one gene copy from each parent must contain a mutation somewhere in the KIF7 gene and be passed on to the child [3]. Characteristics of this syndrome include absence or poor development of the area connecting the left and right parts of the brain, an abnormally large head, increased distance between facial features (eyes), poor motor skills, mental retardation [2], extra fingers and toes, many facial deformities [3], and cleft palate [5]. This is considered a rare disorder and is placed on the NIH Office of Rare Diseases (fewer than 200,000 cases) rare disease list [8]. Lifespan may range from stillbirth to normal expectancy depending on pregnancy complications and severity of the disorder [2,3,5]. In mild cases, the subjects have been shown to live relatively normal lives, but with developmental delays [2].

Joubert syndrome is a rare autosomal recessive genetic disorder that affects the cerebellum, an area of the brain that controls balance and coordination.

Joubert syndrome is one of the many genetic syndromes associated with syndromic retinitis pigmentosa. The syndrome was first identified in 1969 by pediatric neurologist Marie Joubert in Montreal, Quebec, Canada, while working at the Montreal Neurological Institute and McGill University.