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.

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.

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 signs and symptoms of Kaufman oculocerebrofacial syndrome are consistent with the following:

- High palate

- Microcephaly

- Constipation

- Intellectual disability

- Muscular hypotonia

- Nystagmus

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.

The incidence of this condition is <1 per million population. It is found only in females as all affected males die before birth. Teeth with large roots (radiculomegaly), heart defects, and small eyes (microphthalmia) are the characteristic triad found in this syndrome.

Typical features of the condition include:

- Face

- Deep set eyes

- Broad nasal tip divided by a cleft

- Eyes

- Microphthalmia (small eyes)

- Early cataracts

- Glaucoma

- Teeth

- Radiculomegaly (teeth with very large roots)

- Delayed loss of primary teeth

- Missing (oligodontia) or abnormally small teeth

- Misaligned teeth

- Defective tooth enamel.

- Heart defects

- Atrial and/or ventricular defects

- Mitral valve prolapse

- Mild mental retardation and conductive or sensorineural hearing loss may occur.

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.

Coffin–Lowry syndrome is a severe mental retardation associated with abnormalities of:

- Growth

- "In utero" growth is normal but post natal growth is retarded. Patients are sometimes microcephalic.

- Cardio-vascular

- Cardiac abnormalities affect 15% of the patients.

- Skeleton

- Progressive kyphoscoliosis affects 1 in 2 patients. Micrognathia is also associated with this syndrome.

- Patients may also have an underdeveloped upper jaw bone, abnormally prominent brows, or widely spaced eyes.

- Vision and audition

- Auditory abnormalities are frequent and often present. Vision abnormalities are not often present.

The diagnosis is based on the following clinical findings:

- microcephaly

- clinodactyly and shortness of index and little fingers

- syndactyly of 2nd & 3rd and 4th & 5th toe

- short palpebral fissures

- esophageal and/or duodenal atresia

Diagnosis of MSS is based on clinical symptoms, magnetic resonance imaging (MRI) of the brain (cerebellar atrophy particularly involving the cerebellar vermis), and muscle biopsy.

It can be associated with mutations of the SIL1 gene, and a mutation can be found in about 50% of cases.

Differential diagnosis includes Congenital Cataracts Facial Dysmorphism Neuropathy (CCFDN), Marinesco–Sjögren like syndrome with chylomicronemia, carbohydrate deficient glycoprotein syndromes, Lowe syndrome, and mitochondrial disease.

Along with the four aspects of the disorder that give it its name, there are also other common symptoms:

- A downward slant of the forehead

- Delayed bone maturation

- Mental retardation

The ocular abnormalities are generally retinal coloboma and nystagmus.

Symptoms include gingival fibromatosis, associated with hypoplasia of the distal phalanges, nail dysplasia, joint hypermobility, and sometimes hepatosplenomegaly. The nose and pinnae are usually large and poorly developed, which gives the individuals with the syndrome abnormal facial characteristics. Mental retardation may also occur. Both males and females are equally affected. Gingival fibromatosis is usually present at birth or appears short after. The term Zimmermann–Laband was coined by Carl Jacob Witkop in 1971.

VLDLR-associated cerebellar hypoplasia (VLDLRCH; alternative names: dysequilibrium syndrome, DES; nonprogressive cerebellar disorder with mental retardation) is a rare autosomal recessive condition caused by a disruption of the VLDLR gene. First described as a form of cerebral palsy in the 1970s, it is associated with parental consanguinity and is found in secluded communities, with a number of cases described in Hutterite families.

Feingold syndrome is marked by various combinations of microcephaly, limb malformations, esophageal and duodenal atresias, and sometimes learning disability or mental retardation.

Genitopatellar syndrome is a rare condition characterized by genital abnormalities, missing or underdeveloped kneecaps (patellae), intellectual disability, and abnormalities affecting other parts of the body.

Genitopatellar syndrome is also associated with delayed development and intellectual disability, which are often severe. Affected individuals may have an unusually small head (microcephaly) and structural brain abnormalities, including underdeveloped or absent tissue connecting the left and right halves of the brain (agenesis of the corpus callosum).

Clinical manifestations similar to all five described cases of Kapur–Toriello syndrome severe neurodevelopment delay, microphthalmia and/or coloboma, low set and malformed ears, bilateral cleft lip and palate, and constipation. Out of the five cases, two cases presented with imperforated anus/rectal stenosis. Both cases were described in females and, although not definitive, may describe clinical manifestations that differ between sexes.

Wiedemann–Rautenstrauch (WR) syndrome , also known as neonatal progeroid syndrome, is an autosomal recessive progeroid syndrome.

WR was first reported by Rautenstrauch and Snigula in 1977; and the earliest reports made subsequently have been by Wiedemann in 1979, by Devos in 1981, and Rudin in 1988. There have been over 30 cases of WR.

WR is associated with abnormalities in bone maturation, and lipids and hormone metabolism. Affected individuals exhibit intrauterine and postnatal growth retardation, leading to short stature and an aged appearance from birth. They have physical abnormalities including a large head (macrocephaly), sparse hair, prominent scalp veins, inward-folded eyelid (entropion), widened anterior fontanelles, hollow cheeks (malar hypoplasia), general loss of fat tissues under the skin (lipoatrophy), delayed tooth eruption, abnormal hair pattern (hypotrichosis), beaked nose, mild to severe mental retardation and dysmorphism.

Marfan lipodystrophy syndrome (MFLS) has sometimes been confused with Wiedemann–Rautenstrauch syndrome, since the Marfanoid features are progressive and sometimes incomplete. MFLS is caused by mutations near the 3'-terminus of "FBN1" that cause a deficiency of the protein hormone asprosin and progeroid-like symptoms with reduced subcutaneous white adipose tissue.

Individuals with this syndrome typically develop normally until reaching the second decade of their lives but the onset of symptoms has been observed as early as age seven. The first defect observed in individuals who suffer from this condition affects the auditory system and is known as bilateral nerve deafness. Another early symptom is the development of myopia (nearsightedness). In addition to bilateral nerve deafness and myopia, other symptoms that plague infected individuals early in disease progression include ataxia, muscle wasting, severe peripheral neuritic pain sometimes accompanied by elevated spinal fluid protein, and joint stiffness.

The central nervous system (CNS) is affected with deficits in the cerebral cortex which indicate signs of mental retardation even though psychological observations appear relatively normal for individuals studied. Atypical epilepsy is also a common feature of CNS malfunctioning including aphasia expressions, blurred vision, and numbness of the face and limbs.

In the third decade of the condition, individuals develop further visual problems including retinitis pigmentosa, and bilateral cataracts. Sufferers endure the restriction of visual fields, night blindness, and eventually severe or complete blindness.

Individuals with this syndrome exhibit many physical deformities including skeletal, epidermal, and subcutaneous abnormalities. The skeletal problems are characterized by scoliosis and muscle weakness indicative of the kyphoscoliotic type which follow muscle wasting and peripheral neuritis (nerve inflammation). Osteoporosis is also observed in many cases. Skin and subcutaneous atrophy is common as well as skin ulcerations due to inability of the skin to heal. One of the final manifestations of disease is baldness.There is no evidence that the progression of Flynn–Aird syndrome shortens the patient's life-span, but the terrible conditions certainly increase morbidity.

One of the principle symptoms of GAPO syndrome is growth retardation, caused by slow skeletal formation and results in individuals being below average height. Alopecia, or hair loss, is another key indication of GAPO syndrome. Their hair is typically thinly dispersed, and fragile, which often leads to baldness later in life. Similarly, tooth growth is stunted, with teeth failing to emerge form the gums or otherwise develop normally. Atrophy of the optic nerve occurs in approximately one third of individuals. This degradation leads to inhibited peripheral vision, and increased difficulty distinguishing colours.

While not a defining feature, most sufferers of GAPO syndrome have coarse facial features, and abnormal structure of the middle portion of their faces, typically coupled with a large forehead. Individuals with the disease tend to have depressed nose bridges, protruding ears, and abnormally thick lips, though these symptoms are not unique to this disorder.

No direct correlation has been found between GAPO syndrome and mental retardation, though cases of individuals having both have been reported.

Due to the severity of the phenotype, GAPO syndrome can be diagnosed very early on. Most cases can be diagnosed by 6 months of age, and most symptoms will be apparent by age 2.

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.

Young–Simpson syndrome (YSS) is a rare congenital disorder with symptoms including hypothyroidism, heart defects, facial dysmorphism, cryptorchidism in males, hypotonia, mental retardation and postnatal growth retardation.

Other symptoms include transient hypothyroidism, macular degeneration and torticollis. The condition was discovered in 1987 and the name arose from the individuals who first reported the syndrome. An individual with

YSS has been identified with having symptoms to a similar syndrome known as Ohdo Blepharophimosis syndrome, showing that it is quite difficult to diagnose the correct condition based on the symptoms present. Some doctors therefore consider these syndromes to be the same.

The mode of inheritance has had mixed findings based on studies undertaken. One study showed that the parents of an individual with YSS are unrelated and phenotypically normal, indicating a sporadic mutation, thus making it difficult to base the cause of the condition on genetic makeup alone. However, another study was done of an individual with YSS who had first cousins as parents, giving the possibility of autosomal recessive inheritance.

Zimmermann–Laband syndrome (ZLS), also known as Laband–Zimmermann syndrome, and Laband's syndrome, is an extremely rare autosomal dominant congenital disorder.

Oculofaciocardiodental syndrome is a rare X linked genetic disorder.

Branchio-oculo-facial syndrome (BOFS) is a disease that arises from a mutation in the TFAP2A gene. It is a rare autosomal dominant disorder that starts to affect a child's development before birth. Symptoms of this condition include skin abnormalities on the neck, deformities of the ears and eyes, and other distinctive facial features such a cleft lip along with slow growth, mental retardation and premature graying of hair.