Children with Weaver syndrome tend to look similar and have distinctive physical and craniofacial characteristics, which may include several, but not all of the following features:

- Macrocephaly

- Large bifrontal diameter

- Flattened occiput

- Long philtrum

- Retrognathia

- Round face in infancy

- Prominent chin crease

- Large ears

- Strabismus

- Hypertelorism

- Epicanthal folds

- Downslanting palpebral fissures

Other features may include loose skin, thin deep-set nails, thin hair, short ribs, limited elbow and knee extension, camptodactyly, and a coarse, low-pitched voice. Delayed development of motor skills such as sitting, standing, and walking are commonly exhibited in early childhood. Patients with Weaver syndrome typically have mild intellectual disability with poor coordination and balance. They also have some neurological abnormalities such as speech delay, epilepsy, intellectual disability, hypotonia or hypertonia, and behavioral problems.

Following are the features and characteristics that help in spotting this disorder:

- Low birth weight (usually under 5 pounds/2.5 kilograms)

- Delayed growth and small stature

- Developmental delay

- Limb differences (missing limbs or portions of limbs)

- Small head size (microcephaly)

- Thick eyebrows, which typically meet at midline (synophrys)

- Long eyelashes

- Short upturned nose and thin downturned lips

- Long philtrum

- Excessive body hair

- Small hands and feet

- Small widely spaced teeth

- Low-set ears

- Hearing impairments

- Vision abnormalities (e.g., ptosis, nystagmus, high myopia, hypertropia)

- Partial joining of the second and third toes

- Incurved 5th fingers (clinodactyly)

- Gastroesophageal reflux

- Seizures

- Heart defects (e.g., pulmonary stenosis, VSD, ASD, coarctation of the aorta)

- Cleft palate

- Feeding problems

- Hypoplastic genitalia

Children with this syndrome are often found to have long eyelashes, bushy eyebrows and synophrys (joined eyebrows). Body hair can be excessive and affected individuals are often shorter than their immediate family members. They present a characteristic facial phenotype and is recognizable with the Facial Dysmorphology Novel Analysis (FDNA) technology

CdLS can give rise to its own array of complexities. Children with CdLS often suffer from gastrointestinal tract difficulties, particularly gastroesophageal reflux. Vomiting, intermittent poor appetite, constipation, diarrhea or gaseous distention are known to be a regularity in cases where the GI tract problems are acute. Symptoms may range from mild to severe.

CdLS may include behavior problems, including self-stimulation, aggression, self-injury or strong preference to a structured routine. Many children with CdLS exhibit autistic-like behaviors.

Behavior problems in CdLS are not inevitable. Many behavior issues associated with CdLS are reactive (i.e., something happens within the person's body or environment to bring on the behavior) and cyclical (comes and goes). Often, an underlying medical issue causes a change in behavior. Once the medical issue is treated, the behavior diminishes.

Micro syndrome can be identified in people several ways, one of the most common is ocular problems or other physical traits that don't appear natural. It is especially easy to identify micro syndrome in infants and in younger children. Intellectual or developmental disabilities can seriously affect a patient in the way they think and move. So far according to studies all patients have had serious intellectual or developmental disabilities, and hypotonia is found in all the patients during infancy.

Approximately 100 cases have been described in the literature to date.

The facial features are characteristic and include

- Deep set eyes

- Strabismus

- Myopia

- Marked nasal root

- Broad and/or beaked nasal bridge

- Prominent Cupid's bow

- Everted lower lip

- Tented upper lip

- Large mouth

- Widely spaced teeth

- Wide and shallow palate

- Ears with thick and overfolded helix

Most have a smiling appearance.

Intellectual disability is severe. Language is absent or limited to only a few words. Stereotypic movements particularly of the arms, wrists and fingers is almost universal. Hypotonia is common (75%) as is an unsteady gait. All have delayed walking. Other features include a single (simian) palmar crease, long, slender fingers, flat feet and cryptorchidism (in males). Finger clubbing and the presence of fetal pads is common. Hyperventilation occurs in over half and is frequently followed by apnea and cyanosis. During these episodes aerophagia may occur. Constipation is common. Microcephaly and seizures may occur. Hypopigmented skin macules have occasionally been reported.

Symptoms include:

- intellectual disability (more than half of the patients have an IQ below 50)

- microcephaly

- sometimes pancytopenia (low blood counts)

- cryptorchidism

- low birth weight

- dislocations of pelvis and elbow

- unusually large eyes

- low ears

- small chin

Micro syndrome also known as WARBM, and Warburg–Sjo–Fledelius syndrome, is a rare autosomal recessive genetic disorder characterized by microcephaly, microcornea, congenital cataract, intellectual or developmental disability, optic atrophy, and hypogenitalism.

Symptoms of M2DS include infantile hypotonia and failure to thrive, delayed psychomotor development, impaired speech, abnormal or absent gait, epilepsy, spasticity, gastrointestinal motility problems, recurrent infections, and genitourinary abnormalities. Many of those affected by M2DS also fit diagnostic criteria for autism. M2DS can be associated with syndromic facies, namely an abnormally flat back of the head, underdevelopment of the midface, ear anomalies, deep-set eyes, prominent chin, pointed nose, and a flat nasal bridge.

Weaver syndrome (also called Weaver-Smith syndrome) is an extremely rare congenital disorder associated with rapid growth beginning in the prenatal period and continuing through the toddler and youth years. It is characterized by advanced osseous maturation, and distinctive craniofacial, skeletal, and neurological abnormalities. It was first described by Dr. David Weaver in 1974. It is similar to Sotos syndrome.

Associated symptoms range from things such as colobomas of the eyes, heart defects, ichthyosiform dermatosis, intellectual disability, and ear abnormalities. Further symptoms that may be suggested include characteristic facies, hearing loss, and cleft palate.

FG syndrome's major clinical features include intellectual disability, usually severe; hyperactive behavior, often with an outgoing personality; severe constipation, with or without structural anomalies in the anus such as imperforate anus; macrocephaly; severe hypotonia; a characteristic facial appearance due to hypotonia, giving a droopy, "open-mouthed" expression, a thin upper lip, a full or pouting lower lip, and partial or complete loss of the corpus callosum. About a third of reported cases of individuals with FG syndrome die in infancy, usually due to respiratory infection; premature death is rare after infancy.

Associated with agenesis (loss) of the corpus callosum, intellectual disabilities are common among individuals with FG syndrome. Motor ability is also impaired as a result of having FG syndrome and its effects on the development of neurons. During infancy, problems arise in the gastrointestinal and gastroesophageal systems of the body. The most common gastrointestinal problems include constipation from imperforated anuses and gastroesophageal reflux. Cardiopulmonary defects also contribute to roughly 60% of premature deaths in infants with FG syndrome. Of all of the congenital heart defects septal defects are the most common. After infancy, long term survival has been recorded to individuals surviving beyond the age of 50.

This disorder is characterized by unusual facial features, including prominent, wide-set eyes with outer corners that point downward; a short bulbous nose with a flat nasal bridge; ears that are rotated backward; and a widow's peak hairline.

Individuals with Donnai–Barrow syndrome have severe hearing loss caused by abnormalities of the inner ear (sensorineural hearing loss). In addition, they often experience vision problems, including extreme nearsightedness (high myopia), detachment or deterioration of the light-sensitive tissue in the back of the eye (the retina), and progressive vision loss. Some have a gap or split in the colored part of the eye (iris coloboma).

In almost all people with Donnai–Barrow syndrome, the tissue connecting the left and right halves of the brain (corpus callosum) is underdeveloped or absent. Affected individuals may also have other structural abnormalities of the brain. They generally have mild to moderate intellectual disability and developmental delay.

People with Donnai–Barrow syndrome may also have a hole in the muscle that separates the abdomen from the chest cavity (the diaphragm), which is called a diaphragmatic hernia. This potentially serious birth defect allows the stomach and intestines to move into the chest and possibly crowd the developing heart and lungs. An opening in the wall of the abdomen (an omphalocele) that allows the abdominal organs to protrude through the navel may also occur in affected individuals. Occasionally people with Donnai–Barrow syndrome have abnormalities of the intestine, heart, or other organs and scoliosis.

Pitt–Hopkins syndrome is a rare genetic disorder characterized by developmental delay, a wide mouth, distinctive facial features, and intermittent hyperventilation followed by apnea. It is associated with an abnormality within chromosome 18: specifically, it is caused by an insufficient expression of the TCF4 gene.

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)

Cornelia de Lange Syndrome (CdLS) is a very rare genetic disorder present from birth, but not always diagnosed at birth. It causes a range of physical, cognitive, and medical challenges and affects both sexes equally. The syndrome is named after Dutch pediatrician Cornelia Catharina de Lange, who described it.

It is often termed Bushy Syndrome and is also known as Amsterdam dwarfism. It is a genetic disorder that can lead to severe developmental anomalies. It affects the physical and intellectual development of a child. Exact incidence is unknown, but it is estimated at 1 in 10,000 to 30,000.

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).

ATR-16 syndrome affects the blood, development, and brain; symptoms vary based on the specific genes deleted on chromosome 16. Because it is so rare, it is difficult to determine the "core" symptoms of the disease. People with ATR-16 have alpha-thalassemia, a blood disorder where there is less normal hemoglobin in the blood than there should be, and the red blood cells are smaller than they should be (microcytic anemia). Affected children have various characteristic physical features, including clubfoot, "locked" little fingers, microcephaly (small head), hypertelorism (widely spaced eyes), broad, prominent nose bridge, downward-slanted palpebral fissures, small ears, retrognathia, and short neck. Children with ATR-16 syndrome also have mild to moderate intellectual disabilities, developmental delays/growth delays, and speech delays. Some children with ATR-16 have seizures, cryptorchidism (undescended testes), or hypospadias.

GMS syndrome is a syndrome characterised by goniodysgenesis, intellectual disability, and short stature.

LFS is clinically distinguished from other X-linked forms of intellectual disability by the accompanying presence of marfanoid habitus. Marfanoid habitus describes a group of physical features common to Marfan syndrome. Including Marfan syndrome and LFS, marfanoid features of this type have also been observed with several other disorders, one of which is multiple endocrine neoplasia type 2.

In LFS, specific features identified as marfanoid include: a long, narrow face; tall, thin stature; long, slender limbs, fingers and toes (not unlike arachnodactyly) with joint hyperextensibility, shortened halluces (the big toes) and long second toes.

The diagnosis of marfanoid habitus in LFS is often delayed because many of the physical features and characteristics associated with it are usually not evident until adolescence.

Almost all children with Jacobsen syndrome have Intellectual disabilities, which ranges from mild to moderate depending upon the number of the deletion of genes from the chromosome. Children with intellectual disability take more time than normal to learn new things and acquire new skills. They have problems with assembling new information or adapting to novel situations and associating two events or things together.

Most kids with the syndrome have delayed development including delayed speech, motor disabilities, lack of coordination, which makes even simple activities like sitting, standing and walking difficult for these children. Most kids eventually start speaking but in cases with severe intellectual disability language use is highly restricted.

They have distinctive facial features like:

- Small head (microcephaly)

- Pointed forehead, (trigonocephaly)

- Small ears which are low-set

- Widely-spaced eyes (hypertelorism)

- Droopy eyelids (ptosis)

- Broad nasal bridge

- Abnormally thin upper lips

- Downturned corners of the mouth

- Excess skin covering in the inner corner of eyes (epicanthal folds)

Some children also suffer from behavioural problems like distractibility, hyperactivity, impaired communication and social skills which qualifies them for a diagnosis of ASD and ADHD.

Heart defects are very common in children with Jacobsen Syndrome. 88.5% of people with the disorder have Paris-Trousseau syndrome which is a bleeding disorder and causes a lifelong risk of abnormal bleeding and bruising due to dysfunction in the platelets.

Other symptoms may include eye problems, ear and sinus infections, hearing problems, bone deformities, growth hormone deficiency, gastrointestinal problems, kidney malfunctions etc.

Alopecia contractures dwarfism mental retardation syndrome or (ACD mental retardation syndrome) is a developmental disorder which causes mainly baldness and dwarfism in combination with intellectual disability; skeletal anomalies, caries and nearsightedness are also typical.

The ACD mental retardation syndrome was first described in 1980 by Albert Schinzel and only few cases have since been identified in the world. At the time Dr. Schinzel made no conclusion of the hereditary pattern of this syndrome but similarities between cases reported by year 2000 seem to suggest autosomal or x-linked recessive inheritance or possibly a dominant mutation caused by mosaicism as causes of this syndrome.

Cardiofaciocutaneous Syndrome (CFC syndrome) is an extremely rare and serious genetic disorder.

It is characterized by the following:

- Distinctive facial appearance

- Unusually sparse, brittle, curly scalp hair

- A range of skin abnormalities from dermatitis to thick, scaly skin over the entire body (generalized ichthyosis)

- Heart malformations (congenital or appearing later) especially an obstruction of the normal flow of blood from the lower right ventricle of the heart to the lungs (valvar pulmonary stenosis)

- Delayed growth

- Foot abnormalities (extra toe or fusion of two or more toes)

Psychopathology and related behavioral abnormalities are typically seen in LFS, and they may be considered in the diagnosis of the disorder. The most common of these in LFS is an autism-like spectrum disorder, and LFS is considered as one of a number of genetic disorders associated with autism. Additional alterations of psychopathology with behavioral manifestations that have been observed in LFS include: psychotic behavior, schizophrenia, hyperactivity and attention-deficit hyperactivity disorder, aggression, oppositional defiant disorder, obsessive compulsive disorder, extreme shyness, learning disability, cognitive impairment, short-term memory deficit, low frustration tolerance, social dysfunction, lack of impulse control, eating disorder and associated malnutrition, attributed to psychogenic loss of appetite; and pyromania.

While psychiatric conditions like these are to be expected with LFS, there have also been cases of the disorder with some preservation of mental and behavioral abilities, such as problem solving, reasoning and normal intelligence.

The psychopathology of LFS usually exhibits schizophrenia. When schizophrenia is diagnosed in an individual known to be affected by intellectual disability, LFS may be considered in the differential diagnosis of schizophrenia, with confirmation of cause through appropriate psychiatric and genetic evaluation methods.

Common signs of Say–Meyer syndrome are trigonocephaly as well as head and neck symptoms. The head and neck symptoms come in the form of craniosynostosis affecting the metopic suture (the dense connective tissue structure that divides the two halves of the skull in children which usually fuse together by the age of six). Symptoms of Say–Meyer syndrome other than developmental delay and short stature include

- Intellectual disability.

- Low-set ears/posteriorly rotated ears

- Intellectual deficit as well as learning disability

- Intrauterine growth retardation (poor growth of a baby while it is in the mother's womb)

- Posterior fontanel

- Premature synostosis of the lambdoid suture (the fusion of the bones to the joint is premature)

- Narrow forehead

- Trigonocephaly (a frontal bone anomaly that is characterized by a premature fusion of the bones which gives the forehead a triangular shape)

- Hypotelorism or hypertelorism (reduced or increased width between the eyes)

- Craniosynostosis (when one or more seam-like junctions between two bones fuses by turning into bone. This changes the growth pattern of the skull)

- Low birth weight and height

The affected patients sometimes show a highly arched palate, clinodactyly (a defect in which toes or fingers are positioned abnormally) and ventricular septal defect (a heart defect that allows blood to pass directly from left to the right ventricle which is caused by an opening in the septum). Overall, Say–Meyer syndrome impairs growth, motor function, and mental state.

Affected newborns generally have striking neurological defects and seizures. Severely impaired development is common, but disturbances in motor functions may not appear until later in life.

Infants with microcephaly are born with either a normal or reduced head size. Subsequently, the head fails to grow, while the face continues to develop at a normal rate, producing a child with a small head and a receding forehead, and a loose, often wrinkled scalp. As the child grows older, the smallness of the skull becomes more obvious, although the entire body also is often underweight and dwarfed. Development of motor functions and speech may be delayed. Hyperactivity and intellectual disability are common occurrences, although the degree of each varies. Convulsions may also occur. Motor ability varies, ranging from in some to spastic quadriplegia in others.