One person in every 100,000 is affected. Ollier disease is not normally diagnosed until toddler years because it is not very visible.

Marfanoid (or Marfanoid habitus) is a constellation of symptoms resembling those of Marfan syndrome, including long limbs, with an arm span that exceeds the height of the individual, and a crowded oral maxilla, sometimes with a high arch in the palate, arachnodactyly, and hyperlaxity.

Associated conditions include:

- Multiple endocrine neoplasia type 2B

- Homocystinuria

- Ehlers-Danlos syndrome

- Possibly Asperger syndrome

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.

The prognosis is poor; affected individuals are either stillborn or die shortly after birth. The longest survival reported in literature is of 134 days.

This syndrome is transmitted as an autosomal recessive disorder and there is a risk for recurrence of 25% in future pregnancies.

While not always pathological, it can present as a birth defect in multiple syndromes including:

- Catel–Manzke syndrome

- Bloom syndrome

- Coffin–Lowry syndrome

- congenital rubella

- Cri du chat syndrome

- DiGeorge's syndrome

- Ehlers-Danlos syndrome

- fetal alcohol syndrome

- Hallermann-Streiff syndrome

- Hemifacial microsomia (as part of Goldenhar syndrome)

- Juvenile idiopathic arthritis

- Marfan syndrome

- Noonan syndrome

- Pierre Robin syndrome

- Prader–Willi syndrome

- Progeria

- Russell-Silver syndrome

- Seckel syndrome

- Smith-Lemli-Opitz syndrome

- Treacher Collins syndrome

- Trisomy 13 (Patau syndrome)

- Trisomy 18 (Edwards syndrome)

- Wolf–Hirschhorn syndrome

- X0 syndrome (Turner syndrome)

NBCCS has an incidence of 1 in 50,000 to 150,000 with higher incidence in Australia. One aspect of NBCCS is that basal-cell carcinomas will occur on areas of the body which are not generally exposed to sunlight, such as the palms and soles of the feet and lesions may develop at the base of palmar and plantar pits.

One of the prime features of NBCCS is development of multiple BCCs at an early age, often in the teen years. Each person who has this syndrome is affected to a different degree, some having many more characteristics of the condition than others.

It can be detected by the naked eye as well as dental or skull X-Ray testing.

In itself, NSML is not a life-threatening diagnosis, most people diagnosed with the condition live normal lives. Obstructive cardiomyopathy and other pathologic findings involving the cardiovascular system may be a cause of death in those whose cardiac deformities are profound.

Ollier disease carries a high risk of skeletal, visceral and brain malignancy which occurs in approximately 25% of patients. Juvenile granulosa cell tumour has been associated with the disease. The incidence of secondary chondrosarcoma in Ollier disease is not known, but may be as high as 25%, pelvis and shoulder girdle being the commonest locations. A related disorder called Maffucci syndrome named after Angelo Maffucci is characterized by enchondromas associated with multiple hemangiomas which usually occur in the hands and feet. Maffucci syndrome carries a higher risk for cancer.

Cenani–Lenz syndactylism, also known as Cenani–Lenz syndrome or Cenani–syndactylism, is an autosomal recessive congenital malformation syndrome involving both upper and lower extremities.

Marden–Walker syndrome (MWS) is a rare autosomal recessive congenital disorder. It is characterized by blepharophimosis, microcephaly, micrognathia, multiple joint contractures, arachnodactyly, camptodactyly, kyphoscoliosis, and delayed motor development and is often associated with cystic dysplastic kidneys, dextrocardia, Dandy-Walker malformation, and agenesis of corpus callosum".

Cenani–Lenz syndactylism 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.

In a test of the theory that the locus associated with the disorder was at 15q13-q14, FMN1 and GREM1 were eliminated as candidates.

It is associated with "LRP4".

Shprintzen–Goldberg syndrome is a multiple anomaly syndrome that has craniosynostosis, multiple abdominal hernias, cognitive impairment, and other skeletal malformations as key features. Several reports have linked the syndrome to a mutation in the "FBN1" gene, but these cases do not resemble those initially described in the medical literature in 1982 by Shprintzen and Goldberg, and Greally et al. in 1998 failed to find a causal link to FBN1. At this time, the cause of Shprintzen–Goldberg syndrome remains uncertain. The syndrome is rare with fewer than 50 cases described in the medical literature to date.

SHORT syndrome is a medical condition in which affected individuals have multiple birth defects in different organ systems.

It was characterized in 1975.

The RASopathies are developmental syndromes caused by germline mutations (or in rare cases by somatic mosaicism) in genes that alter the Ras subfamily and mitogen-activated protein kinases that control signal transduction, including:

- Capillary malformation-AV malformation syndrome

- Autoimmune lymphoproliferative syndrome

- Cardiofaciocutaneous syndrome

- Hereditary gingival fibromatosis type 1

- Neurofibromatosis type 1

- Noonan syndrome

- Costello syndrome, Noonan-like

- Legius syndrome, Noonan-like

- Noonan syndrome with multiple lentigines, formerly called LEOPARD syndrome, Noonan-like

It has several different types:

- type 1 - Apert syndrome

- type 2 - Crouzon syndrome

- type 3 - Saethre-Chotzen syndrome

- type 5 - Pfeiffer syndrome

A related term, "acrocephalopolysyndactyly" (ACPS), refers to the inclusion of polydactyly to the presentation. It also has multiple types:

- type 1 - Noack syndrome; now classified with Pfeiffer syndrome

- type 2 - Carpenter syndrome

- type 3 - Sakati-Nyhan-Tisdale syndrome

- type 4 - Goodman syndrome; now classified with Carpenter syndrome

- type 5 - Pfeiffer syndrome

It has been suggested that the distinction between "acrocephalosyndactyly" versus "acrocephalopolysyndactyly" should be abandoned.

Via a photo shown on a Facebook page, the mother of a child previously diagnosed with this condition recognised the symptoms and reported them to the family involved, resulting in an immediate diagnosis that medical professionals had overlooked in all earlier consultations.

The highest rate of neurological problems of single suture synostosis are seen in patients with trigonocephaly. Surgery is performed generally before the age of one because of claims of better intellectual outcome. Seemingly surgery does not influence the high incidence of neurodevelopment problems in patients with metopic synostosis. Neurological disorders such as ADHD, ASD, ODD and CD are seen in patients with trigonocephaly. These disorders are usually also associated with decreased IQ. The presence of ADHD, ASD and ODD is higher in cases with an IQ below 85. This is not the case with CD which showed an insignificant increase at an IQ below 85.

Acrocephalosyndactylia (or acrocephalosyndactyly) is the common presentation of craniosynostosis and syndactyly.

In the two predominant mutations of NSML (Y279C and T468M) the mutations cause a loss of catalytic activity of the SHP2 protein (the gene product of the "PTPN11" gene), which is a previously unrecognized behavior for this class of mutations. This interferes with growth factor and related signalling. While further research confirms this mechanism, additional research is needed to determine how this relates to all of the observed effects of NSML.

Neu–Laxova syndrome (also known as Neu syndrome or Neu-Povysilová syndrome, abbreviated as NLS) is a rare autosomal recessive disorder characterized by severe intrauterine growth restriction and multiple congenital malformations. Neu–Laxova syndrome is a very severe disorder, leading to stillbirth or neonatal death. It was first described by Dr. Richard Neu in 1971 and Dr. Renata Laxova in 1972 as a lethal disorder in siblings with multiple malformations. Neu–Laxova syndrome is an extremely rare disorder with less than 100 cases reported in medical literature.

Brooke-Spiegler syndrome is a condition where multiple skin tumors develop from skin structures. Tumors commonly occurring in this syndrome include spiradenomas, trichoepitheliomas, and cylindromas. The tumors are generally benign, but may become malignant. Affected individuals are also at increased risk of developing tumors in tissues other than skin – particularly benign or malignant tumors of the salivary glands.

Tumours in Brooke-Spiegler typically appear in early adulthood and are most often found on the head and neck. In severe cases, the tumors may affect vision or hearing. They can be disfiguring and may contribute to depression or other psychological problems. For unclear reasons, females are often more severely affected than males.

Brooke-Spiegler is rare and its exact incidence is unknown.

It is inherited in an autosomal dominant fashion.

Café au lait spots can arise from diverse and unrelated causes:

- Having six or more café au lait spots greater than 5 mm in diameter before puberty, or greater than 15 mm in diameter after puberty, is a diagnostic feature of neurofibromatosis type I, but other features are required to diagnose NF-1.

- Familial multiple café au lait spots have been observed without NF-1 diagnosis.

- They can be caused by vitiligo in the rare McCune–Albright syndrome.

- Legius syndrome

- Tuberous sclerosis

- Fanconi anemia

- Idiopathic

- Ataxia-telangiectasia

- Basal cell nevus syndrome

- Benign congenital skin lesion

- Bloom syndrome

- Chédiak–Higashi syndrome

- Congenital naevus

- Gaucher disease

- Hunter syndrome

- Jaffe–Campanacci syndrome

- Maffucci syndrome

- Multiple mucosal neuroma syndrome

- Noonan syndrome

- Pulmonary Stenosis

- Silver–Russell syndrome

- Watson syndrome

- Wiskott–Aldrich syndrome

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).

Environmental factors refer for example to maternal smoking and the maternal exposure to amine-containing drugs. Several research groups have found evidence that these environmental factors are responsible for an increase in the risk of craniosynostosis, likely through effects on fibroblast growth factor receptor genes.

On the other hand, a recent evaluation of valproic acid (an anti-epilepticum), which has been implicated as a causative agent, has shown no association with craniosynostosis.

Certain medication (like amine-containing drugs) can increase the risk of craniosynostosis when taken during pregnancy, these are so-called teratogenic factors.