The recurrence of DOOR in siblings and the finding of DOOR syndrome in a few families with consanguinity suggest that the condition is an autosomal recessive genetic condition. Mutations in TBC1D24 have been identified in 9 families.

Hennekam syndrome also known as intestinal lymphagiectasia–lymphedema–mental retardation syndrome, is an autosomal recessive disorder consisting of intestinal lymphangiectasia, facial anomalies, peripheral lymphedema, and mild to moderate levels of growth and intellectual disability.

It is also known as "lymphedema-lymphangiectasia-mental retardation syndrome".

In a subset of patients it is associated with CCBE1 according research published by its namesake, Raoul Hennekam. Other causal mutations were found in the FAT4 gene. Previously, mutations in the FAT4 gene had been only associated with van Maldergem syndrome. The molecular mechanism of the lymphedema phenotype in CCBE1-associated cases was identified as a diminished ability of the mutated CCBE1 to accelerate and focus the activation of the primary lymphangiogenic growth factor VEGF-C.

This disorder is caused by an abnormality of the TBCE gene, the locus for which is on Chromosome 1q42.3. The locus is a 230 kb region of gene with identified deletions and mutations in affected individuals. There are rare cases of the disorder not being due to a TBCE gene abnormality.

There have been 30 cases of Marden-Walker Syndrome reported since 1966. The first case of this was in 1966 a female infant was diagnosed with blepharophimosis, joint contractures, arachnodactyly and growth development delay. She ended up passing at 3 months due to pneumonia.

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.

Although the exact pathology of Dubowitz syndrome is not known yet, it is heritable and classified as an autosomal recessive disease. Furthermore, there is an occasional parental consanguinity. Several cases point to Dubowitz syndrome occurring in monozygotic twins, siblings, and cousins. There is considerable phenotypic variability between cases, especially in regards to intelligence. Although substantial evidence points to the genetic basis of this disorder, the phenotypic similarity is found in fetal alcohol syndrome. Further studies need to be done to determine whether this environmental agent effects the expression of the genotype. Breakdown of chromosomes is known to occur.

In a newborn boy thought to have Fryns syndrome, Clark and Fenner-Gonzales (1989) found mosaicism for a tandem duplication of 1q24-q31.2. They suggested that the gene for this disorder is located in that region. However, de Jong et al. (1989), Krassikoff and Sekhon (1990), and Dean et al. (1991) found possible Fryns syndrome associated with anomalies of chromosome 15, chromosome 6, chromosome 8(human)and chromosome 22, respectively. Thus, these cases may all represent mimics of the mendelian syndrome and have no significance as to the location of the gene for the recessive disorder.

By array CGH, Slavotinek et al. (2005) screened patients with DIH and additional phenotypic anomalies consistent with Fryns syndrome for cryptic chromosomal aberrations. They identified submicroscopic chromosome deletions in 3 probands who had previously been diagnosed with Fryns syndrome and had normal karyotyping with G-banded chromosome analysis. Two female infants were found to have microdeletions involving 15q26.2 (see 142340), and 1 male infant had a deletion in band 8p23.1 (see 222400).

The only treatment for MWS is only symptomatic, with multidisciplinary management

Treatment is symptomatic, often addressing indicators associated with peripheral pulmonary artery stenosis. Laryngotracheal calcification resulting in dyspnea and forceful breathing can be treated with bronchodilators including the short and long-acting β2-agonists, and various anticholinergics. Prognosis is good, yet life expectancy depends on the severity and extent of diffuse pulmonary and arterial calcification.

The cause of this condition is apparently due to mutation in the UBE3B gene and is inherited via autosomal recessive manner. This gene is located at molecular location- base pairs 109,477,410 to 109,543,628 and position 24.11 on chromosome 12.

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

Worldwide, it has been documented in 110 persons, 85 of them Finnish. It is a recessive genetic disease. Many people with Mulibrey nanism have parents who are closely related, consanguine. Signs and symptoms are variable, siblings who suffer this disease sometimes do not share the same symptoms.

Johanson–Blizzard syndrome (JBS) is a rare, sometimes fatal autosomal recessive multisystem congenital disorder featuring abnormal development of the pancreas, nose and scalp, with mental retardation, hearing loss and growth failure. It is sometimes described as a form of ectodermal dysplasia.

The disorder is especially noted for causing profound developmental errors and exocrine dysfunction of the pancreas, and it is considered to be an inherited pancreatic disease.

The incidence of Fraser syndrome is 0.043 per 10,000 live born infants and 1.1 in 10,000 stillbirths, making it a rare syndrome.

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.

It has been suggested that AMS is inherited in an autosomal recessive manner. This means the defective gene responsible for the disorder is located on an autosome, and two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder.

The mechanism (or pathogenesis) of Kaufman oculocerebrofacial syndrome appears to begin due to a mutation in the E3 ubiquitin protein ligase. (UBE3B).

One finds that the normal mechanism of UBE3B gene is important in the ubiquitin-proteasome system.The aforementioned system helps to remove proteins that have degraded. However, when not working properly due to the mutation in the UBE3B gene(at least 15 mutations) results in an unstable UBE3B protein which has a negative effect on the ubiquitin-proteasome system.

No specific treatment is available. Management is only supportive and preventive.

Those who are diagnosed with the disease often die within the first few months of life. Almost all children with the disease die by the age of three.

In 2011, it was demonstrated that "de novo" mutations in the gene KAT6B caused YSS.

Sanjad-Sakati syndrome is a rare autosomal recessive genetic condition seen in offspring of Middle Eastern origin. It was first described in Saudi Arabia, but has been seen in Qatari, Kuwaiti, Omani and other children from the Middle East as well as elsewhere. The condition is caused by mutations or deletions in the TBCE gene of Chromosome No.1.

The condition is characterised by a triad of growth and mental retardation, hypoparathyroidism and dysmorphism.

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.

While there is no cure for JBS, treatment and management of specific symptoms and features of the disorder are applied and can often be successful. Variability in the severity of JBS on a case-by-case basis determines the requirements and effectiveness of any treatment selected.

Pancreatic insufficiency and malabsorption can be managed with pancreatic enzyme replacement therapy, such as pancrelipase supplementation and other related methods.

Craniofacial and skeletal deformities may require surgical correction, using techniques including bone grafts and osteotomy procedures. Sensorineural hearing loss can be managed with the use of hearing aids and educational services designated for the hearing impaired.

Special education, specialized counseling methods and occupational therapy designed for those with mental retardation have proven to be effective, for both the patient and their families. This, too, is carefully considered for JBS patients.

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.

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.

Researchers are also investigating the genetic similarities between Dubowitz Syndrome and Smith-Lemli-Opitz syndrome (SLOS). Patients with SLOS and Dubowitz syndromes experience many of the same abnormalities, and the two disorders are hypothesized to be linked. A characteristic of SLOS is a low cholesterol level and a high 7-dehydrocholesterol level. Cholesterol is essential for several key functions of the body, including cell membrane structure, embryogenesis, and steroid and sex hormone synthesis. Impaired cholesterol biosynthesis or transport possibly accounts for most of the symptoms of both SLOS and Dubowitz. Although only a few patients with Dubowitz Syndrome have been identified with altered cholesterol levels, researchers are exploring whether Dubowitz Syndrome, like SLOS, carries a link to a defect in the cholesterol biosynthetic pathway.

The exact biochemical pathology of the disease is still under research because of the low prevalence of the disease and the wide array of symptoms associated with it. Several studies have focused on different aspects of the disease to try to find its exact cause and expression. One study examined the specific oral features in one patient. Another found abnormalities in the brain, such as corpus callosum dysgenesis, an underdeveloped anterior pituitary and a brain stalk with an ectopic neurohypophysis.