OSLAM syndrome is a rare autosomal dominant hereditary disorder. Its name is an initialism of "osteosarcoma, limb anomalies, and erythroid macrocytosis with megaloblastic marrow syndrome". OSLAM syndrome was recognised and described by Mulvilhill "" as a syndrome that increases susceptibility to tumours and is characterised by an impaired regulation of bone and marrow development.

Individuals with OSLAM syndrome have an elevated risk of bone cancer, limb abnormalities, and enlarged red blood cells.

Bannayan–Riley–Ruvalcaba syndrome is associated with enlarged head and benign mesodermal hamartomas (multiple hemangiomas, and intestinal polyps). Dysmorphy as well as delayed neuropsychomotor development can also be present. The head enlargement does not cause widening of the ventricles or raised intracranial pressure; these individuals have a higher risk of developing tumors, as the gene involved in BRRs is phosphatase and tensin homologue.

Some individuals have thyroid issues consistent with multinodular goiter, thyroid adenoma, differentiated non-medullary thyroid cancer,

most lesions are slowly growing. Visceral as well as intracranial involvement may occur in some cases, and can cause bleeding and symptomatic mechanical compression

Since the original identification of Schimmelpenning syndrome, the number of findings has expanded to the point that the syndrome is associated with a considerable constellation of abnormalities. The abnormalities may occur in a variety of combinations, and need not include all three aspects of the classic triad of sebaceous nevus, seizures and mental retardation. In 1998, a literature review by van de Warrenburg et al. found:

- seizures in 67% of cases

- mental retardation in 61% of cases

- ophthalmological abnormalities in 59% of cases

- involvement of other organ systems in 61% of cases

- structural abnormality of cerebrum or cranium in 72% of cases

The major neurological abnormalities include mental retardation to varying extent, seizures, and hemiparesis. Seizures, when present, typically begin during the first year of life. The most common structural central nervous system abnormalities in Schimmelpenning syndrome are hemimegalencephaly and ipselateral gyral malformations.

The major ocular abnormalities are colobomas and choristomas.

Skeletal abnormalities may include dental irregularities, scoliosis, vitamin D-resistant rickets and hypophosphatemia. Cardiovascular abnormalities include ventricular septal defect and co-arctation of the aorta; urinary system issues include horseshoe kidney and duplicated urinary collection system.

Bannayan–Riley–Ruvalcaba syndrome (BRRS) is a rare overgrowth syndrome and hamartomatous disorder with occurrence of multiple subcutaneous lipomas, macrocephaly and hemangiomas. The disease is inherited in an autosomal dominant manner.

The disease belongs to a family of hamartomatous polyposis syndromes, which also includes Peutz–Jeghers syndrome, juvenile polyposis and Cowden syndrome. Mutation of the PTEN gene underlies this syndrome, as well as Cowden syndrome, Proteus syndrome, and Proteus-like syndrome, these four syndromes are referred to as PTEN Hamartoma-Tumor Syndromes.

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

The syndrome is a rare clinical disorder.

- Physical

- Overgrowth

- Accelerated skeletal maturation

- Dysmorphic facial features

- Prominent eyes

- Bluish sclerae

- Coarse eyebrows

- Upturned nose

- Radiologic examination

- Accelerated osseous maturation

- Phalangeal abnormalities

- Tubular thinning of the long bones

- Skull abnormalities

- Mental

- Often associated with intellectual disability (of variable degree)

The key affected features of this condition are described in its name.

Scalp: There are raised nodules over the posterior aspect of the scalp, covered by scarred non-hair bearing skin.

Ears: The shape of the pinnae is abnormal, with the superior edge of the pinna being turned over more than usual. The size of the tragus, antitragus and lobule may be small.

Nipples: The nipples are absent or rudimentary. The breasts may be small or virtually absent.

Other features of the condition include:

Dental abnormalities: missing or widely spaced teeth

Syndactyly: toes or fingers may be partially joined proximally

Renal abnormalities: renal hypoplasia, pyeloureteral duplication

Eye abnormalities: Cataract, coloboma of the iris and asymmetric pupils.

Bloom syndrome is characterized by genome instability. The most prominent features include short stature and a rash on the face that develops early in life when exposed to the sun. The skin rash is erythematous, telangiectatic, infiltrated, and scaly, it can appear across the nose, on the cheeks and around the lips. As well as these areas the rash will develop on any other sun-exposed areas including, the backs of the hands and neck. Other clinical features include a high-pitched voice; distinct facial features, including a long, narrow face, micrognathism, and prominent nose and ears; pigmentation changes of the skin including hypo-pigmented and hyper-pigmented areas, cafe-au-lait spots, and telangiectasias (dilated blood vessels), which can appear on the skin and eyes. Moderate immune deficiency, characterized by deficiency in certain immunoglobulin classes has also been related to BS, leading to recurrent pneumonia and ear infections. Most individuals with Bloom syndrome are born with a low birth weight. Hypogonadism is characterized by a failure to produce sperm, hence infertility in males, and premature cessation of menses (premature menopause), hence sub-fertility in females. However, several women with Bloom syndrome have had children. The most serious and common complication of Bloom syndrome is cancer. Other complications of the disorder include chronic obstructive lung disease, diabetes, and learning disabilities. There is no evidence that mental retardation is more common in Bloom syndrome than in other people. People with Bloom Syndrome have a shortened life expectancy; the average life span is approximately 27 years. Bloom syndrome shares some features with Fanconi anemia possibly because there is overlap in the function of the proteins mutated in this related disorder.

Multiple hamartoma syndrome is a syndrome characterized by more than one hamartoma.

It is sometimes equated with Cowden syndrome. However, MeSH also includes Bannayan–Zonana syndrome (that is, Bannayan–Riley–Ruvalcaba syndrome) and Lhermitte–Duclos disease under this description. Some articles include Cowden syndrome, Bannayan–Riley–Ruvalcaba syndrome, and at least some forms of Proteus syndrome and Proteus-like syndrome under the umbrella term PTEN hamartoma tumor syndromes (PHTS).

People with Aarskog-Scott syndrome often have distinctive facial features, such as widely spaced eyes (hypertelorism), a small nose, a long area between the nose and mouth (philtrum), and a widow's peak hairline. They frequently have mild to moderate short stature during childhood, but their growth usually catches up with that of their peers during puberty. Hand abnormalities are common in this syndrome and include short fingers (brachydactyly), curved pinky fingers (fifth finger clinodactyly), webbing of the skin between some fingers (cutaneous syndactyly), and a single crease across the palm. Other abnormalities in people with Aarskog-Scott syndrome include heart defects and a split in the upper lip (cleft lip) with or without an opening in the roof of the mouth (cleft palate).

Most males with Aarskog-Scott syndrome have a shawl scrotum, in which the scrotum surrounds the penis instead of hanging below. Less often, they have undescended testes (cryptorchidism) or a soft out-pouching around the belly-button (umbilical hernia) or in the lower abdomen (inguinal hernia).

The intellectual development of people with Aarskog-Scott syndrome varies widely. Some may have mild learning and behavior problems, while others have normal intelligence. In rare cases, severe intellectual disability has been reported.

There is a range of signs and symptoms including cleft lip or palate, mental retardation and various forms of ectodermal dysplasia. Additional symptoms may include fused eyelids, absent nails, delayed bone growth and dry skin. It is believed that this syndrome follows an autosomal dominant pattern of inheritance with incomplete penetrance, and caused by a mutation affecting the TP63 gene. It has been suggested that this syndrome, AEC syndrome and Rapp–Hodgkin syndrome may be variations of the same disease.

There is no specific treatment or cure for individuals affected with this type of syndrome, though some of the abnormal physical features may be surgically correctable.

Schimmelpenning syndrome is a neurocutaneous condition characterized by one or more sebaceous nevi, usually appearing on the face or scalp, associated with anomalies of the central nervous system, ocular system, skeletal system, cardiovascular system, and genitourinary system.

Synonyms include: "Linear nevus sebaceous syndrome (LNSS)", "Schimmelpenning-Feuerstein-Mims syndrome", "Feuerstein-Mims syndrome", "sebaceous nevus syndrome", "Solomon syndrome", and "Jadassohn's nevus phakomatosis". "Nevus" is sometimes spelled "naevus" and "sebaceous" may also be spelled "sebaceus". "Epidermal nevus syndrome" is sometimes used as a synonym, but more often as a broader term referring to Schimmelpenning syndrome in addition to nevus comedonicus syndrome, CHILD syndrome, Becker's nevus syndrome, and phakomatosis pigmentokeratotica.

The classic Schimmelpenning syndrome diagnosis comprises a triad of sebaceous nevi, seizures, and mental retardation. The condition was first reported by Gustav Schimmelpenning in 1957 and independently reported by Feuerstein and Mims in 1962.

One of the most prominent and visible symptoms of Nevo Syndrome is the prenatal overgrowth, which continues into the infant and toddler stage. This excessive weight gain can be attributed to the low concentrations of growth hormone and insulin growth factor that are normally present to regulate weight gain. Other common symptoms associated with Nevo Syndrome are the outward wrist-drop, edema in hands and feet, undescended testes, low-set ears, hypotonia, the presence of low muscle tone in children, and long tapered fingers, and a highly arched palate.

Bloom syndrome (often abbreviated as BS in literature), also known as Bloom-Torre-Machacek syndrome, is a rare autosomal recessive disorder characterized by short stature, predisposition to the development of cancer and genomic instability. BS is caused by mutations in the BLM gene leading to mutated DNA helicase protein formation. Cells from a person with Bloom syndrome exhibit a striking genomic instability that includes excessive crossovers between homologous chromosomes and sister chromatid exchanges (SCEs). The condition was discovered and first described by New York dermatologist Dr. David Bloom in 1954.

Aarskog–Scott syndrome is a rare disease inherited as X-linked and characterized by short stature, facial abnormalities, skeletal and genital anomalies. This condition mainly affects males, although females may have mild features of the syndrome.

The Aarskog–Scott syndrome (AAS) is also known as the Aarskog syndrome, faciodigitogenital syndrome, shawl scrotum syndrome and faciogenital dysplasia.

Overgrowth syndromes in children constitute a group of rare disorders that are typical of tissue hypertrophy. Individual overgrowth syndromes have been shown to overlap with regard to clinical and radiologic features. The details of the genetic bases of these syndromes are unfolding. Any of the three embryonic tissue layers may be involved.The syndromes may manifest in localized or generalized tissue overgrowth. Latitudinal and longitudinal growth may be affected. Nevertheless, the musculoskeletal features are central to the diagnosis of some syndromes such as Proteus syndrome. The time of presentation of children with overgrowth syndromes is an important contributor to the differential diagnosis. Children with some overgrowth syndromes such as Klippel-Trenaunay-Weber syndrome can be readily detectable at birth. In contrast other overgrowth syndromes such as Proteus syndrome usually present in the postnatal period characteristically between the 2nd and 3rd year of life. In general, children with overgrowth syndromes are at increased risk of embryonic tumor development.

Examples of overgrowth syndromes include; Beckwith-Wiedemann syndrome, Proteus syndrome, Sotos syndrome, neurofibromatosis, Simpson-Golabi-Behmel syndrome, Weaver syndrome, Sturge–Weber syndrome, Macrocephaly-capillary malformation, CLOVES syndrome, fragile X syndrome and Klippel-Trenaunay-Weber syndrome.

Scalp–ear–nipple syndrome (also known as "Finlay–Marks syndrome") is a condition associated with aplasia cutis congenita.

Pearson syndrome is a mitochondrial disease characterized by sideroblastic anemia and exocrine pancreas dysfunction. Other clinical features are failure to thrive, pancreatic fibrosis with insulin-dependent diabetes and exocrine pancreatic deficiency, muscle and neurologic impairment, and, frequently, early death. It is usually fatal in infancy. The few patients who survive into adulthood often develop symptoms of Kearns-Sayre syndrome.

It is caused by a deletion in mitochondrial DNA. Pearson syndrome is very rare, less than hundred cases have been reported in medical literature worldwide.

The syndrome was first described by pediatric hematologist and oncologist Howard Pearson in 1979; the deletions causing it were discovered a decade later.

Costello syndrome, also called faciocutaneoskeletal syndrome or FCS syndrome, is a rare genetic disorder that affects many parts of the body. It is characterized by delayed development and delayed mental progression, distinctive facial features, unusually flexible joints, and loose folds of extra skin, especially on the hands and feet. Heart abnormalities are common, including a very fast heartbeat (tachycardia), structural heart defects, and overgrowth of the heart muscle (hypertrophic cardiomyopathy). Infants with Costello syndrome may be large at birth, but grow more slowly than other children and have difficulty feeding. Later in life, people with this condition have relatively short stature and many have reduced levels of growth hormones. It is a RASopathy.

Beginning in early childhood, people with Costello syndrome have an increased risk of developing certain cancerous and noncancerous tumors. Small growths called papillomas are the most common noncancerous tumors seen with this condition. They usually develop around the nose and mouth or near the anus. The most frequent cancerous tumor associated with Costello syndrome is a soft tissue tumor called a rhabdomyosarcoma. Other cancers also have been reported in children and adolescents with this disorder, including a tumor that arises in developing nerve cells (neuroblastoma) and a form of bladder cancer (transitional cell carcinoma).

Costello Syndrome was discovered by Dr Jack Costello, a New Zealand Paediatrician in 1977. He is credited with first reporting the syndrome in the Australian Paediatric Journal, Volume 13, No.2 in 1977.

Little is known about the natural history of Roberts syndrome due to its wide clinical variability. The prognosis of the disease depends on the malformations, as the severity of the malformations correlates with survival. The cause of death for most fatalities of Roberts syndrome have not been reported; however, five deaths were reportedly due to infection.

The following are observations that have been made in individuals with cytogenetic findings of PCS/HR or ESCO2 mutations:

- The symptom of prenatal growth retardation is the most common finding and can be moderate to severe. Postnatal growth retardation can also be moderate to severe and correlates with the degree of severity of limb and craniofacial malformations.

- In limb malformations, the upper limbs are typically more severely affected than the lower limbs. There have been many cases of only upper limb malformation.

- In hand malformations, the thumb is most often affected, followed by the fifth finger (the little finger). In severe cases, the patient may only have three fingers and in rare cases only one.

- In craniofacial malformations, mildly affected individuals will have no abnormalities of the palate. The most severely affected will have a fronto-ethmoid-nasal-maxillary encephalocele.

- The severity of limb malformations and craniofacial malformations is correlated.

- Other abnormalities can occur in different parts of the body, including:

- Heart- atrial septal defects, ventricular septal defects, patent ductus arteriosus

- Kidneys- polycystic kidney, horseshoe kidney

- Male Genitals- enlarged penis, cryptorchidism

- Female Genitals- enlarged clitoris

- Hair- sparse, silvery-blonde scalp hair

- Cranial Nerve Paralysis, Moyamoya disease, Stroke, Intellectual disability

Respiratory complications are often cause of death in early infancy.

1. Blood. With Pearson Syndrome, the bone marrow fails to produce white blood cells called neutrophils. The syndrome also leads to anemia, low platelet count, and aplastic anemia It may be confused with transient erythroblastopenia of childhood.

2. Pancreas. Pearson Syndrome causes the exocrine pancreas to not function properly because of scarring and atrophy

Individuals with this condition have difficulty absorbing nutrients from their diet which leads to malabsorption. infants with this condition generally do not grow or gain weight.

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

Orofaciodigital syndrome 1 (OFD1), also called Papillon-League and Psaume syndrome, is an X-linked congenital disorder characterized by malformations of the face, oral cavity, and digits with polycystic kidney disease and variable involvement of the central nervous system.