Complete trisomy 8 causes severe effects on the developing fetus and can be a cause of miscarriage.

Complete trisomy 8 is usually an early lethal condition, whereas trisomy 8 mosaicism is less severe and individuals with a low proportion of affected cells may exhibit a comparatively mild range of physical abnormalities and developmental delay. Individuals with trisomy 8 mosaicism are more likely to survive into childhood and adulthood, and exhibit a characteristic and recognizable pattern of developmental abnormalities. Common findings include retarded psychomotor development, moderate to severe mental retardation, variable growth patterns which can result in either abnormally short or tall stature, an expressionless face, and many musculoskeletal, visceral, and eye abnormalities, as well as other anomalies. A deep plantar furrow is considered to be pathognomonic of this condition, especially when seen in combination with other associated features. The type and severity of symptoms are dependent upon the location and proportion of trisomy 8 cells compared to normal cells.

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)

Trisomy 8, also known as Warkany syndrome 2, is a human chromosomal disorder caused by having three copies (trisomy) of chromosome 8. It can appear with or without mosaicism.

Many of the physical features associated with the disorder are congenital. Characteristic craniofacial abnormalities typically include a long, narrow head that is disproportionate to the body size, a broad and prominent forehead, and a triangular-shaped face with a hypoplastic midface, pointed chin, prominent mouth, fleshy tipped upturned nose, large ears, and full lips. The teeth may be abnormally crowded together in some affected individuals.

Individuals with 3-M syndrome suffer from severe prenatal growth retardation due to growth delays during fetal development resulting in a low birth weight. Growth delays continue after birth throughout childhood and adolescence, ultimately leading to a short stature.

ADULT syndrome features include ectrodactyly, syndactyly, excessive freckling, lacrimal duct anomalies, dysplastic nails, hypodontia, hypoplastic breasts and nipples, hypotrichosis, hypohidrosis, broad nasal bridge, midfacial hypoplasia, exfoliative dermatitis, and xerosis. The lack of facial clefting and ankyloblepharon are important because they exist in ectrodactyly–ectodermal dysplasia–cleft syndrome (EEC) but not in ADULT syndrome.

Acro–dermato–ungual–lacrimal–tooth (ADULT) syndrome is a rare genetic disease. ADULT syndrome is an autosomal dominant form of ectodermal dysplasia, a group of disorders that affects the hair, teeth, nails, sweat glands, and extremities. The syndrome arises from a mutation in the TP63 gene. This disease was previously thought to be a form of ectrodactyly–ectodermal dysplasia–cleft syndrome (EEC), but was classified as a different disease in 1993 by Propping and Zerres.

Greig cephalopolysyndactyly syndrome is a disorder that affects development of the limbs, head, and face. The features of this syndrome are highly variable, ranging from very mild to severe. People with this condition typically have one or more extra fingers or toes (polydactyly) or an abnormally wide thumb or big toe (hallux).

The skin between the fingers and toes may be fused (cutaneous syndactyly). This disorder is also characterized by widely spaced eyes (ocular hypertelorism), an abnormally large head size (macrocephaly), and a high, prominent forehead. Rarely, affected individuals may have more serious medical problems including seizures, mental retardation, and developmental delay.

Schwartz–Jampel syndrome (SJS) is a rare genetic disease caused by a mutation in the HSPG2 gene, which makes the protein perlecan, and causing osteochondrodysplasia associated with myotonia.

Most people with Schwartz–Jampel syndrome have a nearly normal life expectancy.

Affected individuals commonly suffer from photophobia, nystagmus and achromatopsia. Other symptoms affecting vision may include night vision difficulties; optic disc pallor; narrow vessels; macular atrophy with pigment mottling; peripheral deep white dot deposits or retinal pigment epithelium (RPE) alterations in the inferonasal retina; decreased foveal and retinal thickness; attenuation of retinal lamination; hyperreflectivity in the choroids (due to RPE and choriocapillaris atrophy); impairment of color vision; and progressive loss of vision with advancing age.

In line with ameleogenesis imperfecta, affected members may display teeth yellow-brown in colour, dysplastic, presenting numerous caries; reduced enamel layer prone to posteruptive failure; and abnormality of morphology involving dentine.

Berdon syndrome, also called Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIH syndrome), is an autosomal recessive fatal genetic disorder affecting newborns. In a 2011 study of 227 children with the syndrome, "the oldest survivor [was] 24 years old." The Ann Arbor News reported a five year old survivor at the end of 2015.

It is more prevalent in females, 7 females to 3 males, and is characterized by constipation and urinary retention, microcolon, giant bladder (megacystis), intestinal hypoperistalis, hydronephrosis, and dilated small bowel. The pathological findings consist of an abundance of ganglion cells in both dilated and narrow areas of the intestine. It is a familial disturbance of unknown cause.

Walter Berdon "et al." in 1976 first described the condition in five female infants, two of whom were sisters. All had marked dilatation of the bladder and some had hydronephrosis and the external appearance of prune belly. The infants also had microcolon and dilated small intestines.

Relationships between the disease and perlecan deficiency have been studied.

Although confirmation of a specific genetic marker is in a significant number of individuals, there are no tests to clearly determine if this is what a person has. As a 'syndrome' a diagnosis is typically given for children upon confirmation of the presence of several 'symptoms' listed below. Symptoms are Intrauterine Growth Restriction (IUGR) combined with some of the following:

- Often small for gestational age (SGA) at birth (birth weight less than 2.8 kg)

- Feeding problems: the baby is uninterested in feeding and takes only small amounts with difficulty

- Hypoglycemia

- Excessive sweating as a baby, especially at night, and a greyness or pallor of the skin. This may be a symptom of hypoglycemia

- Triangular shaped face with a small jaw and a pointed chin that tends to lessen slightly with age. The mouth tends to curve down

- A blue tinge to the whites of the eyes in younger children

- Head circumference may be of normal size and disproportionate to a small body size

- Wide and late-closing fontanelle

- Clinodactyly

- Body asymmetry: one side of the body grows more slowly than the other

- Continued poor growth with no "catch up" into the normal centile lines on growth chart

- Precocious puberty (occasionally)

- Low muscle tone

- Gastroesophageal reflux disease

- A striking lack of fat

- Late closing of the opening between the heart hemispheres

- Constipation (sometimes severe)

The average adult height for patients without growth hormone treatment is 4'11" for males and 4'7" for females.

Respiratory complications are often cause of death in early infancy.

The symptoms of Sly syndrome are similar to those of Hurler syndrome (MPS I). The symptoms include:

- in the head, neck, and face: coarse (Hurler-like) facies and macrocephaly, frontal prominence, premature closure of sagittal lambdoid sutures, and J-shaped sella turcica

- in the eyes: corneal opacity and iris coloboma

- in the nose: anteverted nostrils and a depressed nostril bridge

- in the mouth and oral areas: prominent alveolar processes and cleft palate

- in the thorax: usually pectus carinatum or exacavatum and oar-shaped ribs; also a protruding abdomen and inguinal or umbilical hernia

- in the extremities: talipes, an underdeveloped ilium, aseptic necrosis of femoral head, and shortness of tubular bones occurs

- in the spine: kyphosis or scoliosis and hook-like deformities in thoracic and lumbar vertebrate

- in the bones: dysostosis multiplex

In addition recurrent pulmonary infections occur. Hepatomegaly occurs in the gastrointestinal system. Splenomegaly occurs in the hematopoietic system. Inborn mucopolysaccharide metabolic disorders due to β-glucuronidase deficiency with granular inclusions in granulocytes occurs in the biochemical and metabolic systems. Growth and motor skills are affected, and mental retardation also occurs.

Rudiger syndrome is a congenital disorder characterized by the association of severe growth retardation with abnormalities of the extremities, urogenital abnormalities and facial abnormalities. It has been described in a family where an affected brother and sister died as infants. Both autosomal recessive and autosomal dominant inheritance have been suggested with the disorder.

The features ectrodactyly, ectodermal dysplasia and cleft palate have been described with Rudiger syndrome, giving it the rarely used designation "EEC syndrome". However, this is not to be confused with the formal EEC syndrome associated with chromosome 7.

It was characterized in 1971.

Clinical expressions of PPS are highly variable, but include the following:

- Limb findings: an extensive web running from behind the knee down to the heel (90%), malformed toenails, and webbed toes.

- Facial findings: cleft palate with or without cleft lip (75%), pits in the lower lip (40%), and fibrous bands in the mouth known as syngnathia (25%).

- Genital findings (50%): hypoplasia of the labia majora, malformation of the scrotum, and cryptorchidism.

Revesz syndrome is a fatal disease that causes exudative retinopathy and bone marrow failure. Other symptoms include severe aplastic anemia, intrauterine growth retardation, fine sparse hair, fine reticulate skin pigmentation, ataxia due to cerebellar hypoplasia, and cerebral calcifications. Its effects are similar to that of Hoyeraal-Hreidarsson syndrome. It is a variant of dyskeratosis congenita.

Jalili syndrome is a genetic disorder characterized by the combination of cone-rod dystrophy of the retina and amelogenesis imperfecta. It was characterized in 1988 by Dr. I. K. Jalili and Dr. N. J. D. Smith, following the examination of 29 members of an inbred, Arab family living within the Gaza Strip.

Worth syndrome, also known as benign form of Worth hyperostosis corticalis generalisata with torus platinus, autosomal dominant osteosclerosis, autosomal dominant endosteal hyperostosis or Worth disease, is a rare autosomal dominant congenital disorder that is caused by a mutation in the LRP5 gene. It is characterized by increased bone density and benign bony structures on the palate.

Sly syndrome, also called mucopolysaccharidosis type VII (MPS 7), is an autosomal recessive lysosomal storage disease characterized by a deficiency of the enzyme β-glucuronidase, a lysosomal enzyme. Sly syndrome belongs to a group of disorders known as mucopolysaccharidoses, which are lysosomal storage diseases. In Sly syndrome, the deficiency in β-glucuronidase leads to the accumulation of certain complex carbohydrates (mucopolysaccharides) in many tissues and organs of the body.

It was named after its discoverer William S. Sly, an American biochemist who has spent nearly his entire academic career at Saint Louis University.

Revesz syndrome is a genetic disease thought to be caused by short telomeres. Patients with Revesz syndrome have presented with heterozygous mutations in TINF2 gene which is located on chromosome 14q12. There is no treatment for this disease yet.

Popliteal pterygium syndrome (PPS) is an inherited condition affecting the face, limbs, and genitalia. The syndrome goes by a number of names including the "popliteal web syndrome" and, more inclusively, the "facio-genito-popliteal syndrome". The term PPS was coined by Gorlin "et al.." in 1968 on the basis of the most unusual anomaly, the popliteal pterygium (a web behind the knee).

Silver–Russell syndrome (SRS), also called Silver–Russell dwarfism or Russell–Silver syndrome (RSS) is a growth disorder occurring in approximately 1/50,000 to 1/100,000 births. In the United States it is usually referred to as Russell–Silver syndrome, and Silver–Russell syndrome elsewhere. It is one of 200 types of dwarfism and one of five types of primordial dwarfism and is one of the few forms that is considered treatable in some cases.

There is no statistical significance of the syndrome occurring preferentially in either males or females.

The spotty skin pigmentation and lentigines occur most commonly on the face, especially on the lips, eyelids, conjunctiva and oral mucosa. Cardiac myxomas may lead to embolic strokes and heart failure and may present with fever, joint pain, shortness of breath, diastolic rumble and tumor plop. Myxomas may also occur outside the heart, usually in the skin and breast. Endocrine tumors may manifest as disorders such as Cushing syndrome. The most common endocrine gland manifestation is an ACTH-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD).

The LAMB acronym refers to lentigines, atrial myxomas, and blue nevi. NAME refers to nevi, atrial myxoma, myxoid neurofibromas, and ephelides.

Testicular cancer, particularly Sertoli cell type, is associated with Carney syndrome. Thyroid and pancreas cancer may also occur.

Although J Aidan Carney also described Carney's triad it is entirely different.