Not all of the DOOR symptoms are consistently present. They can vary in severity, and additional features can be noted in individuals affected by DOOR syndrome.

Some of these additional features are:

- Polyhydramnios (increased amniotic fluid during pregnancy) and increased nuchal fold during pregnancy

- Specific facial features such as a large nose

- Severe and sometimes refractory seizures, abnormalities on the magnetic resonance imaging of the brain

- Increased 2-oxoglutaric acid in the blood and urine - this compound is made or used by several enzymes

- Finger-like thumbs

- Visual impairment

- Peripheral neuropathy (nerves conducting sensation from extremities to the brain) and insensivity to pain

Intellectual impairment is present in all reported cases, but the severity can vary widely. The prognosis in terms of survival also varies greatly from early childhood till adulthood.

Children with the Sanjad Sakati syndrome have a triad of:

a) hypoparathyroidism (with episodes of hypocalcemia, hypocalcemic tetany and hypocalcemic seizures.

b) severe mental retardation and

c) dysmorphism.

Typically, children with this syndrome are born low-birth-weight due to intrauterine growth retardation. At birth, there is dysmorphism, which is later typified into the features described below. The child is stunted, often with demonstrable growth hormone deficiency and has moderate to severe mental retardation, mainly as a consequence of repeated seizures brought on by the low blood ionic calcium levels. The immuno-reactive parathormone levels are low to undetectable, with low calcium and high phosphate levels in the blood.

"Dysmorphism" is most evident on the face, with the following features:

- Long narrow face

- Deep-set, small eyes

- Beaked nose

- Large, floppy ears

- Small head (microcephaly) and

- Thin lips with a long philtrum.

The syndrome causes cerebellar ataxia (balance and coordination problems), mental retardation, congenital cataracts in early childhood, muscle weakness, inability to chew food, thin brittle fingernails, and sparse hair.

Small stature, mild to severe mental retardation and dysarthria (slow, imprecise speech) are usually present.

Various skeletal abnormalities (e.g., curvature of the spine) and hypergonadotropic hypogonadism often occur.

Muscle weakness is progressive, but life expectancy is near normal.

SFMS affects the skeletal and nervous system. This syndrome's external signs would be an unusual facial appearance with their heads being slightly smaller and unusually shaped, a narrow face which is also called dolichocephaly, a large mouth with a drooping lower lip that are held open, protruding upper jaw, widely spaced upper front teeth, an underdeveloped chin, cleft palate and exotropied-slanted eyes with drooping eyelids.

Males who have SFMS have short stature and a thin body build. Also skin is lightly pigmented with multiple freckles. They may have scoliosis and chest abnormalities.

Affected boys have reduced muscle tone as infants and young children. X-rays sometimes show that their bones are underdeveloped and show characteristics of younger bones of children. Boys usually under the age of 10 have reduced muscle tone but later, patients with SFMS over the age of 10 have increased muscle tone and reflexes that cause spasticity. Their hands are short with unusual palm creases with short, shaped fingers and foot abnormalities are shortened and have fused toes and usually mild.

They have an absent of a spleen and the genitals may also show undescended testes ranging from mild to severe that leads to female gender assignment.

People who have SFMS have severe mental retardation. They are sometimes restless, behavior problems, seizures and severe delay in language development. They are self-absorbed with reduced ability to socialize with others around them. They also have psychomotor retardation which is the slowing-down of thoughts and a reduction of physical movements. They have cortical atrophy or degeneration of the brain's outer layer. Cortical atrophy is usually founded in older affected people.

Other features include:

- Stunting

- Small hands and feet with long, tapering fingers and clinodactyly

- Dental anomalies in the form of malalignment and malocclusion

In another study of six patients, the patients were investigated further. They were found to have low levels of IGF-1 and markedly retarded bone age.

The combination of muscular hypotonia and fixed dilated pupils in infancy is suspicious of Gillespie syndrome. Early onset partial aniridia, cerebellar ataxia, and mental retardation are hallmark of syndrome. The iris abnormality is specific and seems pathognomonic of Gillespie syndrome. The aniridia consisting of a superior coloboma and inferior iris hypoplasia, foveomacular dysplasia.

Atypical Gillespie syndrome associated with bilateral ptosis, exotropia, correctopia, iris hypoplasia, anterior capsular lens opacities, foveal hypoplasia, retinal vascular tortuosity, and retinal hypopigmentation.

Neurological signs ar nystagmus, mild craniofacial asymmetry, axial hypotonia, developmental delay, and mild mental retardation. Mariën P did not support the prevailing view of a global mental retardation as a cardinal feature of Gillespie syndrome but primarily reflect cerebellar induced neurobehavioral dysfunctions following disruption of the cerebrocerebellar anatomical circuitry that closely resembles the "cerebellar cognitive and affective syndrome" (CeCAS).

Congenital pulmonary stenosis and helix dysplasia can be associated.

Movements of the eyes left to right.

Little or no movement in the arms or legs.

Respiratory troubles/problems.

DOOR (deafness, onychdystrophy, osteodystrophy, and mental retardation) syndrome is a genetic disease which is inherited in an autosomal recessive fashion. DOOR syndrome is characterized by mental retardation, sensorineural deafness, abnormal nails and phalanges of the hands and feet, and variable seizures. A similar deafness-onychodystrophy syndrome is transmitted as an autosomal dominant trait and has no mental retardation. Some authors have proposed that it may be the same as Eronen Syndrome, but since both disorders are extremely rare it is hard to make a determination.

The main symptoms are given by its name: dry, scaly skin (ichthyosis), absence of hair (atrichia) and excessive sensitivity to light (photophobia). Additional features include short stature, mental retardation, seizures and a tendency for respiratory infections.

The diagnosis of PMD is often first suggested after identification by magnetic resonance imaging (MRI) of abnormal white matter (high T2 signal intensity, i.e. T2 lengthening) throughout the brain, which is typically evident by about 1 year of age, but more subtle abnormalities should be evident during infancy. Unless there is a family history consistent with sex-linked inheritance, the condition is often misdiagnosed as cerebral palsy. Once a "PLP1" or "GJA12" mutation is identified, prenatal diagnosis or preimplantation genetic diagnostic testing is possible.

Marinesco–Sjögren syndrome (MSS), sometimes spelled Marinescu–Sjögren syndrome, is a rare autosomal recessive disorder.

Gillespie syndrome, also called aniridia, cerebellar ataxia and mental deficiency. is a rare genetic disorder. The disorder is characterized by partial aniridia (meaning that part of the iris is missing), ataxia (motor and coordination problems), and, in most cases, intellectual disability. It is heterogeneous, inherited in either an autosomal dominant or autosomal recessive manner. Gillespie syndrome was first described by American ophthalmologist Fredrick Gillespie in 1965.

Presenting at birth, features of the disorder include moderately severe IUGR, microcephaly, craniosynostosis, moderately severe post uterine growth retardation, deafness, deep set eyes, cryptorchidism, truncal obesity and acanthosis nigricans, small teeth, prognathism, dislocated radial heads without generalized skeletal dysplasia, however, tall vertebrae, moderate mental retardation, hypothyroidism, insulin resistance, hypoparathyroidism.

Cohen syndrome (also known as Pepper syndrome or Cervenka syndrome, named after Michael Cohen, William Pepper and Jaroslav Cervenka, who researched the illness) is a genetic disorder.

BFPP is a cobblestone-like cortical malformation of the brain. Disruptions of cerebral cortical development due to abnormal neuronal migration and positioning usually lead to cortical disorders, which includes cobblestone lissencephaly. Cobblestone lissencephaly is typically seen in three different human congenital muscular dystrophy syndromes: Fukuyama congenital muscular dystrophy, Walker-Warburg syndrome, and muscle-eye-brain disease. In cobblestone lissencephaly, the brain surface actually has a bumpy contour caused by the presence of collections of misplaced neurons and glial cells that have migrated beyond the normal surface boundaries of the brain. Sometimes regions populated by these misplaced cells have caused a radiologic misdiagnosis of polymicrogyria. However, the presence of other abnormalities in these cobblestone lissencephaly syndromes, including ocular anomalies, congenital muscular dystrophy, ventriculomegaly, and cerebellar dysplasia, usually distinguishes these disorders from polymicrogyria. There are no anatomopathologic studies that have characterized the pattern of cortical laminar alterations in patients with GPR56 gene mutations, but it has been suggested that the imaging characteristics of BFPP, including myelination defects and cerebellar cortical dysplasia, are reminiscent of those of the so-called cobblestone malformations (muscle-eye-brain disease and Fukuyama congenital muscular dystrophy) that are also associated with N-glycosylation defects in the developing brain.

Lissencephaly ("smooth brain") is the extreme form of pachygyria. In lissencephaly, few or no sulci are seen on the cortical surface, resulting in a broad, smooth appearance to the entire brain. Lissencephaly can be radiologically confused with polymicrogyria, particularly with low-resolution imaging, but the smoothness and lack of irregularity in the gray-white junction, along with markedly increased cortical thickness, distinguishes lissencephaly.

GPR56 mutation also can cause a severe encelphalopathy which is associated with electro clinical features of the Lennox-Gastaut syndrome. Lennox-Gastaut syndrome can be cryptogenic or symptomatic, but the symptomatic forms have been associated with multiple etiologies and abnormal cortical development. BFPP caused by GPR56 mutations is a representation of a malformation of cortical development that causes Lennox-Gastaut Syndrome.

Polymicrogyria usually gets misdiagnose with pacygyria so therefore it needs to be distinguished from pachygyria. Pachygyria is a distinct brain malformation in which the surface folds are excessively broad and sparse. Pachygyria and polymicrogyria may look similar on low-resolution neuroimaging such as CT because the cortical thickness can appear to be increased and the gyri can appear to be broad and smooth in both conditions. This is why higher resolution neuroimaging are needed such as an MRI.

Microlissencephalic patients suffer from spasticity, seizures, severe developmental delay and intellectual disabilities with survival varying from days to years. Patients may also have dysmorphic craniofacial features, abnormal genitalia, and arthrogryposis.

Microlissencephaly may arise as a part of Baraitser-Winter syndrome which comprises also ptosis, coloboma, hearing loss and learning disability.

Moreover, it is the distinct developmental brain abnormality in "microcephalic osteodysplastic primordial dwarfism" (MOPD1). Microlissencephaly may be accompanied by micromelia as in Basel-Vanagaite-Sirota syndrome ( Microlissencephaly-Micromelia syndrome).

Alpha-thalassemia mental retardation syndrome (ATRX), also called alpha-thalassemia X-linked mental retardation, nondeletion type or ATR-X syndrome, is a condition caused by a mutated gene. Females with this mutated gene have no specific signs or features, but may demonstrate skewed X chromosome inactivation. Hemizygous males tend to be moderately intellectually disabled and have physical characteristics including coarse facial features, microcephaly (small head size), hypertelorism (widely spaced eyes), a depressed nasal bridge, a tented upper lip, and an everted lower lip. Mild or moderate anemia, associated with alpha-thalassemia, is part of the condition.

It is associated with "ATRX".

Microlissencephaly Type A or Norman-Roberts syndrome (NRS): a microlissencephaly with thick cortex without infratentorial anomalies.

Other clinical features may include: a bitemporal narrowing, a broad nasal root. There is postnatal growth retardation, severe mental retardation associated with pyramidal spasticity and epilepsy. This entity could be identical to "lissencephaly with cerebellar hypoplasia type B" (LCHb), and therefore linked to mutations in "RELN" gene.

The term "multisystem developmental disorder" has also been used to describe various developmental disorders. These include:

- Alagille syndrome, an autosomal dominant disorder with a wide range of features and manifestations. Its five most significant features are chronic cholestasis, a condition where bile cannot flow from the liver to the duodenum, occurring in 95% of cases; heart abnormalities (over 90%); butterfly vertebrae; posterior embryotoxon and a distinctive face (prominent forehead, deep-set eyes, and a pointed chin).

- Rubinstein-Taybi syndrome, a mental retardation syndrome characterized by broad thumbs, facial abnormalities, and big toes alongside mental retardation.

- Williams syndrome, a neurodevelopmental disorder characterized by a unique profile of strengths and deficits; most with the condition have mild mental retardation but have grammatical and lexical abilities above what would be expected from their IQs. They are hypersocial and empathetic, but social isolation is commonly experienced.

- Proteus syndrome, a congenital disorder causing disproportionate growth of skin, bone, and other tissues.

- Asphyxiating thoracic dysplasia, a autosomal recessive skeletal disorder with an estimated prevalence of between 1 in 100,000 and 1 in 130,000 live births.

Smith–Fineman–Myers syndrome (SFMS1), congenital disorder that causes birth defects. This syndrome was named after 3 men, Richard D. Smith, Robert M. Fineman and Gart G. Myers who discovered it around 1980.

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.

Camisa disease (or Vohwinkel variant with ichthyosis) is the variant form of Vohwinkel syndrome, characterized by ichthyosis and normal hearing.

It is associated with loricrin.

It was characterized in 1984 and 1988.

Alopecia contractures dwarfism mental retardation syndrome or (ACD mental retardation syndrome) is a developmental disorder which causes mainly baldness and dwarfism in combination with intellectual disability; skeletal anomalies, caries and nearsightedness are also typical.

The ACD mental retardation syndrome was first described in 1980 by Albert Schinzel and only few cases have since been identified in the world. At the time Dr. Schinzel made no conclusion of the hereditary pattern of this syndrome but similarities between cases reported by year 2000 seem to suggest autosomal or x-linked recessive inheritance or possibly a dominant mutation caused by mosaicism as causes of this syndrome.

There are different tests or methods used to determine GPR56 expression or visuals of the brain to analyze the specific sections that are affected. These tests for example, using animals such as mice, RNAi, Behavioral assay, Electron microscopy, CT scan, or MRI demonstrate different results that concludes an affected BFPP patient. MRI's reveal either irregularity to the cortical surface suggestive of multiple small folds or an irregular, scalloped appearance of the gray matter-white matter junction.

Neuroimaging The diagnosis of polymicrogyria is typically made by magnetic resonance imaging (MRI) since computed tomography (CT) and other imaging methods generally do not have high enough resolution or adequate contrast to identify the small folds that define the condition. The cerebral cortex often appears abnormally thick as well because the multiple small gyri are fused, infolded, and superimposed in appearance.

Neuropathology Gross neuropathologic examination reveals a pattern of complex convolutions to the cerebral cortex, with miniature gyri fused and superimposed together, often resulting in an irregular brain surface. The cortical ribbon can appear excessively thick as a result of the infolding and fusion of multiple small gyri.

Microscopic examination demonstrates that the cerebral cortex is in fact abnormally thin and has abnormal lamination; typically the cortex is unlayered or has four layers, in contrast to the normal six layers. The most superficial layers between adjacent small gyri appear fused, with the pia (layer of the meninges) bridging across multiple gyri. Prenatal diagnosis for BFPP is also available for pregnancies at risk if the GPR56 mutations have been identified in an affected family member.

Mental retardation and microcephaly with pontine and cerebellar hypoplasia (MICPCH), also known as Mental retardation, X-linked, syndromic, Najm type (MRXSNA), is a rare genetic disorder of infants characterised by intellectual disability and pontocerebellar hypoplasia.

The disorder is associated with a mutation in the "CASK" gene which is transmitted in an X-linked manner. As with the vast majority of genetic disorders, there is no known cure to MICPCH.

The following values seem to be aberrant in children with CASK gene defects: lactate, pyruvate, 2-ketoglutarate, adipic acid and suberic acid, which seems to backup the proposal that CASK affects mitochondrial function. It is also speculated that phosphoinositide 3-kinase in the inositol metabolism is impacted in the disease, causing folic acid metabolization problems.