Cardiac anomalies are the most common congenital malformation in individuals with tetrasomy 18p. However, there is no pathognomatic heart defect associated with the condition. Patent ductus arteriosus is the most common defect. Septal defects (ventricular septal defects and atrial septal defects) are also common, as are patent foramina ovalia. Other cardiac anomalies include mitral valve regurgitation, mitral valve prolapse, bicuspid pulmonary valve, hypoplastic transverse aortic arch, tricuspid valve regurgitation, right ventricular hypertrophy, and pulmonic stenosis.

In males, cryptorchidism is common. Abnormal genitalia in females is not a common feature. Renal abnormalities have been reported in a minority of patients. Horseshoe kidney and bladder diverticuli have been reported. Other abdominal malformations, including pyloric stenosis and hernias, have also been reported, though they are present in only a minority of patients.

Orthopedic anomalies also occur relatively frequently, with hip dysplasia being the most common orthopedic issue. Clubfoot and rocker bottom feet have also been reported.

Myelomeningocele is another known feature associated with tetrasomy 18p.

Heart-hand syndrome type 1 is more commonly known as Holt–Oram syndrome. Is the most prevalent form of heart-hand syndrome.

It is an autosomal dominant disorder that affects bones in the arms and hands (the upper limbs) and may also cause heart problems. The syndrome includes an absent radial bone in the arms, an atrial septal defect, and a first degree heart block.

Neonatal complications (apart from congenital anomalies) are common. In a paper published in 2010, 41 of 42 individuals had some type medical problem in the first days of life, the most common being feeding difficulties. Respiratory difficulty and jaundice are also relatively frequent.

Heart-hand syndromes are a group of rare diseases that manifest with both heart and limb deformities.

, known heart-hand syndromes include Holt–Oram syndrome, Berk–Tabatznik syndrome, heart-hand syndrome type 3, brachydactyly-long thumb syndrome, patent ductus arteriosus-bicuspid aortic valve syndrome and heart hand syndrome, Slovenian type.

Nasodigitoacoustic syndrome is congenital and is characterized by a number of nasal, facial and cranial features. These include a broad and high, sometimes depressed nasal bridge (top of the nose, between the eyes) and a flattened nasal tip. This can give the nose a shortened, arch-like appearance. Hypertelorism (unusually wide-set eyes), prominent frontal bones and supraorbital ridge (the eyebrow ridge), bilateral epicanthic folds (an extra flap of skin over the eyelids), a broad forehead and an overall enlarged head circumference have also been observed. A bulging of the upper lip with an exaggerated cupid's bow shape, and maxillary hypoplasia (underdevelopment of the upper jaw) with retraction have also been reported.

Several anomalies affecting the digits (fingers and toes) have been observed with the syndrome. A broadening of the thumbs and big toes (halluces) was reported in two brothers. The broadening was apparent in all distal phalanges of the fingers, although the pinkies were unaffected yet appeared to be clinodactylic (warped, or bent toward the other fingers). Additional eports described this broadness of the thumbs and big toes, with brachydactyly (shortness) in the distal phalanges of the other digits except the pinkies in affected individuals. On X-rays of a two-year-old boy with the disorder, the brachydactyly was shown to be caused by shortening of epiphyses (joint-ends) of the distal phalanges. The broadness and brachydactyly of the big toes in particular may give them a stunted, rounded and stub-like appearance.

The auditory, or "acoustic" abnormalities observed with the syndrome include sensorineural hearing loss and hoarseness. Two affected Turkish brothers with a mild form of this hearing loss, and a hoarse voice were reported. A laryngoscopic examination of both brothers revealed swelling of the vocal cords, and a malformed epiglottis. Sensorineural-associated hearing impairment and hoarsness was also observed in a 10-year-old girl and her father, and in a number of other cases.

Other characteristics seen with the syndrome include developmental delay, growth retardation, pulmonary stenosis (an obstruction of blood-flow from the right ventricle of the heart to the pulmonary artery) with associated dyspnea (shortness of breath), and renal agenesis (failure of the kidneys to develop during the fetal period). Undescended testes, hyperactivity and aggressive behavior have also been noted.

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.

Infants with Emanuel syndrome have weak muscle tone (hypotonia) and fail to gain weight and grow at the expected rate (failure to thrive). Their development is significantly delayed, and most affected individuals have severe to profound intellectual disability. Other features of Emanuel syndrome include an unusually small head (microcephaly), distinctive facial features, and a small lower jaw (micrognathia). Ear abnormalities are common, including small holes in the skin just in front of the ears (preauricular pits or sinuses). About half of all affected infants are born with an opening in the roof of the mouth (cleft palate) or a high arched palate. Males with Emanuel syndrome often have genital abnormalities. Additional signs of this condition can include heart defects and absent or unusually small (hypoplastic) kidneys; these problems can be life-threatening in infancy or childhood.

The three most common symptoms of Opitz G/BBB syndrome (both type I & II) are hypertelorism (exceptionally wide-spaced eyes), laryngo-tracheo-esophalgeal defects (including clefts and holes in the palate, larynx, trachea and esophagus) and hypospadias (urinary openings in males not at the tip of the penis) (Meroni, Opitz G/BBB syndrome, 2012). Abnormalities in the larynx, trachea and esophagus can cause significant difficulty breathing and/or swallowing and can result in reoccurring pneumonia and life-threatening situations. Commonly, there may be a gap between the trachea and esophagus, referred to as a laryngeal cleft; which can allow food or fluid to enter the airway and make breathing and eating a difficult task.

Genital abnormalities like a urinary opening under the penis (hypospadias), undescended testes (cryptorchidism), underdeveloped scrotum and a scrotum divided into two lobes (bifid scrotum) can all be commonplace for males with the disease.

Developmental delays of the brain and nervous system are also common in both types I and II of the disease. 50% of people with Opitz G/BBB Syndrome will experience developmental delay and mild intellectual disability. This can impact motor skills, speech and learning capabilities. Some of these instances are likened to autistic spectrum disorders. Close to half of the people with Opitz G/BBB Syndrome also have a cleft lip (hole in the lip opening) and possibly a cleft palate (hole in the roof of the mouth), as well. Less than half of the people diagnosed have heart defects, imperforate anus (obstructed anal opening), and brain defects. Of all the impairments, female carriers of X-linked Type I Opitz G/BBB Syndrome usually only have ocular hypertelorism.

Carpenter syndrome presents several features:

- Tower-shaped skull (craniosynostosis)

- Additional or fused digits (fingers and toes)

- Obesity

- Reduced height

Intellectual disability is also common with the disorder, although some patients may have average intellectual capacity.

Robinow noted the resemblance of affected patients' faces to that of a fetus, using the term "fetal facies" to describe the appearance of a small face and widely spaced eyes. Clinical features also may include a short, upturned nose, a prominent forehead, and a flat nasal bridge. The upper lip may be "tented", exposing dental crowding, "tongue tie", or gum hypertrophy.

Though the eyes do not protrude, abnormalities in the lower eyelid may give that impression. Surgery may be necessary if the eyes cannot close fully. In addition, the ears may be set low on the head or have a deformed pinna.

Patients suffer from dwarfism, short lower arms, small feet, and small hands. Fingers and toes may also be abnormally short and laterally or medially bent. The thumb may be displaced and some patients, notably in Turkey, experience ectrodactyly. All patients often suffer from vertebral segmentation abnormalities. Those with the dominant variant have, at most, a single butterfly vertebra. Those with the recessive form, however, may suffer from hemivertebrae, vertebral fusion, and rib anomalies. Some cases resemble Jarcho-Levin syndrome or spondylocostal dysostosis.

Genital defects characteristically seen in males include a micropenis with a normally developed scrotum and testes. Sometimes, testicles may be undescended, or the patient may suffer from hypospadias. Female genital defects may include a reduced size clitoris and underdeveloped labia minora. Infrequently, the labia majora may also be underdeveloped. Some research has shown that females may experience vaginal atresia or haematocolpos.

The autosomal recessive form of the disorder tends to be much more severe. Examples of differences are summarized in the following table:

Different areas of deletion are associated with different symptoms. Deletions from the centromere to 13q32 or any deletions including the 13q32 band are associated with slow growth, intellectual disability, and congenital malformations. Deletions from 13q33 to the end of the chromosome are associated with intellectual disability. Intellectual disabilities range from very mild to very severe, and can co-occur with behavioral disorders and/or autism spectrum disorders.

At birth, the main symptoms include low weight (due to intrauterine growth restriction), hypotonia, and feeding difficulties. Infants may also have cleft palate.

13q deletion syndrome gives a characteristic appearance to affected individuals, potentially including microphthalmia (small eyes), hypertelorism (wide-set eyes), thin forehead, high palate, underdeveloped midface, small mouth, small nose, broad, flat nasal bridge, short neck, low hairline, irregular or wrongly positioned teeth, low-set ears, micrognathia (small jaw), tooth enamel defects, short stature, microcephaly (small head), a prominent, long philtrum, and earlobes turned inwards.

Congenital heart disease is associated with 13q deletion syndrome. Common defects include atrial septal defect, tetralogy of Fallot, ventricular septal defect, patent ductus arteriosus, pulmonary stenosis, and coarctation of the aorta. Defects of the endocrine system, digestive system, and genitourinary system are also common. These include underdevelopment or agenesis of the pancreas, adrenal glands, thymus, gallbladder, and thyroid; Hirschsprung's disease; gastric reflux, imperforate anus, retention testis, ectopic kidney, renal agenesis, and hydronephrosis.

A variety of brain abnormalities are also associated with 13q deletion. They can include epilepsy, craniosynostosis (premature closing of the skull bones), spastic diplegia, cerebral hypotrophy, underdevelopment or agenesis of the corpus callosum, cerebellar hypoplasia, deafness, and, rarely, hydrocephalus, Dandy–Walker syndrome, and spina bifida. The eyes can be severely damaged and affected individuals may be blind. They may also have coloboma of the iris or choroid, strabismus, nystagmus, glaucoma, or cataracts.

Other skeletal malformations are found with 13q deletion syndrome, including syndactyly, clubfoot, clinodactyly, and malformations of the vertebrae and/or thumbs.

Deletions that include the 13q32 band, which contains the brain development gene ZIC2, are associated with holoprosencephaly; they are also associated with hand and foot malformations. Deletions that include the 13q14 band, which contains the tumor suppressor gene Rb, are associated with a higher risk of developing retinoblastoma, which is more common in XY children. Deletion of the 13q33.3 band is associated with hypospadias. Other genes in the potentially affected region include NUFIP1, HTR2A, PDCH8, and PCDH17.

Aneuploidy is often fatal, but in this case there is "X-inactivation" where the effect of the additional gene dosage due to the presence of extra X chromosomes is greatly reduced.

Much like Down syndrome, the mental effects of 49,XXXXY syndrome vary. Impaired speech and behavioral problems are typical. Those with 49,XXXXY syndrome tend to exhibit infantile secondary sex characteristics with sterility in adulthood and have some skeletal anomalies. Skeletal anomalies include:

- Genu valgum

- Pes cavus

- Fifth finger clinodactyly

The effects also include:

- Cleft palate

- Club feet

- Respiratory conditions

- Short or/and broad neck

- Low birth weight

- Hyperextensible joints

- Short stature

- Narrow shoulders

- Coarse features in older age

- Hypertelorism

- Epicanthal folds

- Prognathism

- Gynecomastia (rare)

- Muscular hypotonia

- Hypoplastic genitalia

- Cryptorchidism

- Congenital heart defects

- A very round face in infancy

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.

There is a wide range of congenital problems associated with kabuki syndrome with large differences between affected individuals. Some of the common problems are heart defects, urinary tract anomalies, hearing loss, hypotonia, recurrent ear infections and postnatal growth deficiency. Other characteristics include skeletal abnormality, joint laxity, short stature, and unusual dermatoglyphic patterns.

In terms of development, mild to moderate intellectual disability is a common feature. Also, children with kabuki syndrome often have distinctive behavioral features. A few have normal intelligence, most of whom have learning difficulties such as struggling with fine motor, speech skills, and memory.

There is no indication that the life expectancy of individuals with kabuki syndrome is shortened. Most medical issues are resolved with medical intervention. The fact that there are relatively few adults known with this syndrome is probably related to its recent discovery in 1980 in Japan and around 1990 in Europe and America.

The main characteristics of 49,XXXXX are intellectual disability, short stature and craniofacial abnormalities. Other physical traits include the following:

- Small head

- Ear abnormalities

- Widely spaced eyes with upward slanting palpebral fissures and epicanthal folds

- Short neck

- Broad nose with a depressed nasal bridge

- Hyperextension of the elbows

- Dental abnormalities and cleft palate

- Clinodactyly of the 5th finger

- Deformities of the feet

- Heart defects

The facial appearance of individuals with this syndrome include long eyelids with turning up of the lateral third of the lower eyelid, a broad and depressed nasal tip, large prominent earlobes, and a cleft or high-arched palate.

Other clinical features often include scoliosis, short fifth finger, persistence of fingerpads, and X-ray abnormalities of the vertebrae, hands, and hip joints.

The following is a list of symptoms that have been associated with Roberts syndrome:

- Bilateral Symmetric Tetraphocomelia- a birth defect in which the hands and feet are attached to shortened arms and legs

- Prenatal Growth Retardation

- Hypomelia (Hypoplasia)- the incomplete development of a tissue or organ; less drastic than aplasia, which is no development at all

- Oligodactyly- fewer than normal number of fingers or toes

- Thumb Aplasia- the absence of a thumb

- Syndactyly- condition in which two or more fingers (or toes) are joined together; the joining can involve the bones or just the skin between the fingers

- Clinodactyly- curving of the fifth finger (little finger) towards the fourth finger (ring finger) due to the underdevelopment of the middle bone in the fifth finger

- Elbow/Knee Flexion Contractures- an inability to fully straighten the arm or leg

- Cleft Lip- the presence of one or two vertical fissures in the upper lip; can be on one side (unilateral) or on both sides (bilateral)

- Cleft Palate- opening in the roof of the mouth

- Premaxillary Protrusion- upper part of the mouth sticks out farther than the lower part of the mouth

- Micrognathia- small chin

- Microbrachycephaly- smaller than normal head size

- Malar Hypoplasia- underdevelopment of the cheek bones

- Downslanting Palpebral Fissures- the outer corners of the eyes point downwards

- Ocular Hypertelorism- unusually wide-set eyes

- Exophthalmos- a protruding eyeball

- Corneal Clouding- clouding of the front-most part of the eye

- Hypoplastic Nasal Alae- narrowing of the nostrils that can decrease the width of the nasal base

- Beaked Nose- a nose with a prominent bridge that gives it the appearance of being curved

- Ear Malformations

- Intellectual disability

- Encephalocele (only in severe cases)- rare defect of the neural tube characterized by sac-like protrusions of the brain

Mortality is high among those severely affected by Roberts syndrome; however, mildly affected individuals may survive to adulthood

Carpenter Syndrome belongs to a group of rare genetic disorders known as acrocephalopolysyndactyly, abbreviated ACPS (RN, 2007). There were originally five types of ACPS, but this number has been decreased because they have been found to be closely related to one another or to other disorders (Paul A. Johnson, 2002).

The most common physical manifestation of Carpenter Syndrome is early fusing of the fibrous cranial sutures which results in an abnormally pointed head. The fusion of the skull bones is evident from birth (National Organization for Rare Disorders, Inc., 2008). Babies’ mobile cranial bones form a cone shape as the pass through the birth canal and soon thereafter return to a normal shape; however, a baby affected by carpenter syndrome maintains a cone shaped head.

A baby affected by Carpenter Syndrome will also display malformations of the face. An individual affected by the syndrome may have broad cheeks, a flat nasal bridge, and a wide upturned nose with abnormally large nasal openings. Their ears will most commonly be low, unevenly set, and malformed in structure. In addition to these facial abnormalities, individuals also have an underdeveloped maxilla and/ or mandible with a highly arched and narrow palate which makes speech a very difficult skill to master. Teeth are usually very late to come in and will be undersized and spaced far apart (Carpenter Syndrome-description).

Other physical abnormalities often associated with Carpenter Syndrome include extra digits. Extra toes are more commonly seen than fingers. Often both the toes and fingers are webbed, a process that occurs before the sixth week gestational period. Often their digits will be abnormally short, and the fingers are commonly missing an interphalangeal joint. Roughly half of the babies born with Carpenter Syndrome have some type of heart defect, and seventy five percent of individuals with this disease will experience some degree of development delay due to mild mental retardation (Carpenter Syndrome-description).

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.

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

Of those fetuses that do survive to gestation and subsequent birth, common abnormalities may include:

- Nervous system

- Intellectual disability and motor disorder

- Microcephaly

- Holoprosencephaly (failure of the forebrain to divide properly).

- Structural eye defects, including microphthalmia, Peters' anomaly, cataract, iris or fundus (coloboma), retinal dysplasia or retinal detachment, sensory nystagmus, cortical visual loss, and optic nerve hypoplasia

- Meningomyelocele (a spinal defect)

- Musculoskeletal and cutaneous

- Polydactyly (extra digits)

- Cyclopia

- Proboscis

- Congenital trigger digits

- Low-set ears

- Prominent heel

- Deformed feet known as rocker-bottom feet

- Omphalocele (abdominal defect)

- Abnormal palm pattern

- Overlapping of fingers over thumb

- Cutis aplasia (missing portion of the skin/hair)

- Cleft palate

- Urogenital

- Abnormal genitalia

- Kidney defects

- Other

- Heart defects (ventricular septal defect) (Patent Ductus Arteriosus)

- Dextrocardia

- Single umbilical artery

13q deletion syndrome is a rare genetic disease caused by the deletion of some or all of the large arm of human chromosome 13. It causes intellectual disability and congenital malformations that affect a variety of organ systems.

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.

X-linked type I Opitz G/BBB Syndrome is diagnosed on clinical findings, but those findings can vary greatly: even within the same family. Manifestations of X-linked type I are classified in the frequent/major findings and minor findings that are found in less than 50% of individuals.

The three major findings that suggest a person has X-linked Type I Opitz G/BBB Syndrome:

1. Ocular hypertelorism (~100% cases)

2. Hypospadias (85-90% cases)

3. Laryngotracheoesophageal abnormalities (60-70%)

Minor findings found in less than 50% of individuals:

1. Developmental delay (especially intellectually)

2. Cleft lip/palate

3. Congenital heart defects

4. Imperforate (blocked) anus

5. Brain defects (especially corpus callosum)

In 1989, Hogdall used ultrasonographs to diagnose X-linked Type I Opitz G/BBB Syndrome after 19 weeks of pregnancy, by identifying hypertelorism (widely-spaced eyes) and hypospadias (irregular urinary tract openings in the penis).

There is also molecular genetic testing available to identify mutations leading to Opitz G/BBB Syndrome. X-linked Type I testing must be done on MID1, since this is the only gene that is known to cause Type I Opitz G/BBB Syndrome. Two different tests can be performed: sequence analysis and deletion/duplication analysis. In the sequence analysis a positive result would detect 15-50% of the DNA sequence mutated, while a deletion/duplication positive result would find deletion or duplication of one or more exons of the entire MID1 gene.

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).