Current research is focusing on clearly defining the phenotype associated with tetrasomy 18p and identifying which genes cause medical and developmental problems when present in four copies.

At present, treatment for tetrasomy 18p is symptomatic, meaning that the focus is on treating the signs and symptoms of the conditions as they arise. The Chromosome 18 Clinical Research Center has published a list of recommended screening and evaluations:

Making a correct diagnosis for a genetic and rare disease is often times very challenging. So the doctors and other healthcare professions rely on the person’s medical history, the severity of the symptoms, physical examination and lab tests to make and confirm a diagnosis.

There is a possibility of interpreting the symptoms of PWS with other conditions such as AVMs and or AVFs. This is because AVMs and AVFs also involve the characteristic overgrowth in soft tissue, bone and brain. Also PWS can be misdiagnosed with Klippel–Trenaunay syndrome (KTS). However, KTS consists of the following: triad capillary malformation, venous malformation, and lymphatic malformation.

Usually a specific set of symptoms such as capillary and arteriovenous malformations occur together and this is used to distinguish PWS from similar conditions. Arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs) are caused by RASA1 mutations as well. Therefore, if all the other tests (discussed below) fail to determine PWS, which is highly unlikely, genetic testing such as sequence analysis and gene-targeted deletion/duplication analysis can be performed to identify possible RASA1 gene mutations.

But PWS can be distinguished from other conditions because of its defining port-wine stains that are large, flat and pink. The port-wine stains and physical examination are enough to diagnose PWS. But additional testing is necessary to determine the extent of the PWS syndrome. The following tests may be ordered by physicians to help determine the appropriate next steps: MRI, ultrasound, CT/CAT scan, angiogram, and echocardiogram.

MRI: This is a high-resolution scan that is used to identify the extent of the hypertrophy or overgrowth of the tissues. This can also be used to identify other complications that may arise a result of hypertrophy.

Ultrasound: this can be necessary to examine the vascular system and determine how much blood is actually flowing through the AVMs.

CT/CAT scan: this scan is especially useful for examining the areas affected by PWS and is helpful for evaluating the bones in the overgrown limb.

Angiogram: an angiogram can also be ordered to get a detailed look at the blood vessels in the affected or overgrown limb. In this test an interventional radiologist injects a dye into the blood vessels that will help see how the blood vessels are malformed.

Echocardiogram: depending on the intensity of the PWS syndrome, an echo could also be ordered to check the condition of the heart.

And PWS often requires a multidisciplinary care. Depending on the symptoms, patients are dependent on: dermatologists, plastic surgeons, general surgeons, interventional radiologists, orthopedists, hematologists, neurosurgeons, vascular surgeons and cardiologists. Since the arteriovenous and capillary malformations cannot be completely reconstructed and depending on the extent and severity of the malformations, these patients may be in the care of physicians for their entire lives.

Prenatal Diagnosis:

- Aymé, "et al." (1989) reported prenatal diagnosis of Fryns syndrome by sonography between 24 and 27 weeks.

- Manouvrier-Hanu et al. (1996) described the prenatal diagnosis of Fryns syndrome by ultrasonographic detection of diaphragmatic hernia and cystic hygroma. The diagnosis was confirmed after termination of the pregnancy. The fetus also had 2 erupted incisors; natal teeth had not been mentioned in other cases of Fryns syndrome.

Differential Diagnosis:

- McPherson et al. (1993) noted the phenotypic overlap between Fryns syndrome and the Pallister–Killian syndrome (601803), which is a dysmorphic syndrome with tissue-specific mosaicism of tetrasomy 12p.

- Veldman et al. (2002) discussed the differentiation between Fryns syndrome and Pallister–Killian syndrome, noting that differentiation is important to genetic counseling because Fryns syndrome is an autosomal recessive disorder and Pallister–Killian syndrome is usually a sporadic chromosomal aberration. However, discrimination may be difficult due to the phenotypic similarity. In fact, in some infants with 'coarse face,' acral hypoplasia, and internal anomalies, the initial diagnosis of Fryns syndrome had to be changed because mosaicism of isochromosome 12p was detected in fibroblast cultures or kidney tissue. Although congenital diaphragmatic hernia is a common finding in both syndromes, bilateral congenital diaphragmatic hernia had been reported only in patients with Fryns syndrome until the report of the patient with Pallister–Killian syndrome by Veldman et al. (2002).

- Slavotinek (2004) reviewed the phenotypes of 52 reported cases of Fryns syndrome and reevaluated the diagnostic guidelines. She concluded that congenital diaphragmatic hernia and distal limb hypoplasia are strongly suggestive of Fryns syndrome, with other diagnostically relevant findings including pulmonary hypoplasia, craniofacial dysmorphism, polyhydramnios, and orofacial clefting. Slavotinek (2004) stated that other distinctive anomalies not mentioned in previous guidelines include ventricular dilatation or hydrocephalus, agenesis of the corpus callosum, abnormalities of the aorta, dilatation of the ureters, proximal thumbs, and broad clavicles.

The diagnosis of this syndrome can be made on clinical examination and perinatal autopsy.

Koenig and Spranger (1986) noted that eye lesions are apparently nonobligatory components of the syndrome. The diagnosis of Fraser syndrome should be entertained in patients with a combination of acrofacial and urogenital malformations with or without cryptophthalmos. Thomas et al. (1986) also emphasized the occurrence of the cryptophthalmos syndrome without cryptophthalmos and proposed diagnostic criteria for Fraser syndrome. Major criteria consisted of cryptophthalmos, syndactyly, abnormal genitalia, and positive family history. Minor criteria were congenital malformation of the nose, ears, or larynx, cleft lip and/or palate, skeletal defects, umbilical hernia, renal agenesis, and mental retardation. Diagnosis was based on the presence of at least 2 major and 1 minor criteria, or 1 major and 4 minor criteria.

Boyd et al. (1988) suggested that prenatal diagnosis by ultrasound examination of eyes, digits, and kidneys should detect the severe form of the syndrome. Serville et al. (1989) demonstrated the feasibility of ultrasonographic diagnosis of the Fraser syndrome at 18 weeks' gestation. They suggested that the diagnosis could be made if 2 of the following signs are present: obstructive uropathy, microphthalmia, syndactyly, and oligohydramnios. Schauer et al. (1990) made the diagnosis at 18.5 weeks' gestation on the basis of sonography. Both the female fetus and the phenotypically normal father had a chromosome anomaly: inv(9)(p11q21). An earlier born infant had Fraser syndrome and the same chromosome 9 inversion.

Van Haelst et al. (2007) provided a revision of the diagnostic criteria for Fraser syndrome according to Thomas et al. (1986) through the addition of airway tract and urinary tract anomalies to the major criteria and removal of mental retardation and clefting as criteria. Major criteria included syndactyly, cryptophthalmos spectrum, urinary tract abnormalities, ambiguous genitalia, laryngeal and tracheal anomalies, and positive family history. Minor criteria included anorectal defects, dysplastic ears, skull ossification defects, umbilical abnormalities, and nasal anomalies. Cleft lip and/or palate, cardiac malformations, musculoskeletal anomalies, and mental retardation were considered uncommon. Van Haelst et al. (2007) suggested that the diagnosis of Fraser syndrome can be made if either 3 major criteria, or 2 major and 2 minor criteria, or 1 major and 3 minor criteria are present in a patient.

If the medical history and the actual exam of the hemangioma look typical for PHACE Syndrome, more tests are ordered to confirm the diagnosis. These tests may include:

- Ultrasound

- Magnetic resonance imaging (MRI)

- Magnetic resonance angiography of the brain (MRA)

- Echocardiogram

- Eye exam by an eye doctor

- Other tests may be needed for diagnosis and treatment

The diagnosis of AOS is a clinical diagnosis based on the specific features described above. A system of major and minor criteria was proposed.

The combination of two major criteria would be sufficient for the diagnosis of AOS, while a combination of one major and one minor feature would be suggestive of AOS. Genetic testing can be performed to test for the presence of mutation in one of the known genes, but these so far only account for an estimated 50% of patients with AOS. A definitive diagnosis may therefore not be achieved in all cases.

Patients with abnormal cardiac and kidney function may be more at risk for hemolytic uremic syndrome

Carrier testing for Roberts syndrome requires prior identification of the disease-causing mutation in the family. Carriers for the disorder are heterozygotes due to the autosomal recessive nature of the disease. Carriers are also not at risk for contracting Roberts syndrome themselves. A prenatal diagnosis of Roberts syndrome requires an ultrasound examination paired with cytogenetic testing or prior identification of the disease-causing ESCO2 mutations in the family.

The causes for PWS are either genetic or unknown. Some cases are a direct result of the RASA1 gene mutations. And individuals with RASA1 can be identified because this genetic mutation always causes multiple capillary malformations. PWS displays an autosomal dominant pattern of inheritance. This means that one copy of the damaged or altered gene is sufficient to elicit PWS disorder. In most cases, PWS can occur in people that have no family history of the condition. In such cases the mutation is sporadic. And for patients with PWS with the absence of multiple capillary mutations, the causes are unknown.

According to Boston’s Children Hospital, no known food, medications or drugs can cause PWS during pregnancy. PWS is not transmitted from person to person. But it can run in families and can be inherited. PWS effects both males and females equally and as of now no racial predominance is found

At the moment, there are no known measures that can be taken in order to prevent the onset of the disorder. But Genetic Testing Registry can be great resource for patients with PWS as it provides information of possible genetic tests that could be done to see if the patient has the necessary mutations. If PWS is sporadic or does not have RASA1 mutation then genetic testing will not work and there is not a way to prevent the onset of PWS.

Trisomy 9 can be detected prenatally with chorionic villus sampling and cordocentesis, and can be suggested by obstetric ultrasonography.

Because trisomy 9 may appear with mosaicism, it is suggested that doctors take samples from multiple tissues when karyotyping for diagnosis.

The symptoms would appear at birth or shortly after birth. The combination of physical symptoms on the child would suggest they have CHILD syndrome. A skin sample examined under a microscope would suggest the characteristics of the syndrome and an X-Ray of the trunk, arms, and legs would help to detect underdeveloped bones. A CT scan would help detect problems of the internal organs.

The overall prognosis is excellent in most cases. Most children with Adams–Oliver syndrome can likely expect to have a normal life span. However, individuals with more severe scalp and cranial defects may experience complications such as hemorrhage and meningitis, leading to long-term disability.

Cytogenetic preparations that have been stained by either Giemsa or C-banding techniques will show two characteristic chromosomal abnormalities. The first chromosomal abnormality is called premature centromere separation (PCS) and is the most likely pathogenic mechanism for Roberts syndrome. Chromosomes that have PCS will have their centromeres separate during metaphase rather than anaphase (one phase earlier than normal chromosomes). The second chromosomal abnormality is called heterochromatin repulsion (HR). Chromosomes that have HR experience separation of the heterochromatic regions during metaphase. Chromosomes with these two abnormalities will display a "railroad track" appearance because of the absence of primary constriction and repulsion at the heterochromatic regions. The heterochromatic regions are the areas near the centromeres and nucleolar organizers. Carrier status cannot be determined by cytogenetic testing. Other common findings of cytogenetic testing on Roberts syndrome patients are listed below.

- Aneuploidy- the occurrence of one or more extra or missing chromosomes

- Micronucleation- nucleus is smaller than normal

- Multilobulated Nuclei- the nucleus has more than one lobe

The diagnosis is usually based on clinical features present at birth.

Ultrasound in the second trimester may show abnormalities associates with NLS, including polyhydramnios, intrauterine growth restriction, microcephaly, proptosis and decreased fetal motility.

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.

The incidence of VACTERL association is estimated to be approximately 1 in 10,000 to 1 in 40,000 live-born infants. It is seen more frequently in infants born to diabetic mothers. While most cases are sporadic, there are clearly families who present with multiple involved members.

Surgical correction is recommended when a constriction ring results in a limb contour deformity, with or without lymphedema.

While no cure for MDS is available yet, many complications associated with this condition can be treated, and a great deal can be done to support or compensate for functional disabilities. Because of the diversity of the symptoms, it can be necessary to see a number of different specialists and undergo various examinations, including:

- Developmental evaluation

- Cardiologists evaluation

- Otolaryngology

- Treatment of seizures

- Urologic evaluation

- Genetic counseling-balanced chromosomal translocation should be excluded in a parents with an affected child are planning another pregnancy, so parents with affected children should visit a genetic counselor.

Treatment is usually confined to such surgical intervention as may be necessary to help the child to develop e.g. jaw distraction/bone grafts, ocular dermoid debulking (see below), repairing cleft palate/lip, repairing heart malformations or spinal surgery. Some patients with Goldenhar syndrome will require assistance as they grow by means of hearing aids or glasses.

Stem cell grafting (womb tissue grafting) has been successfully used to "reprogram" eye dermoids, effectively halting the regrowth of eye dermoids.

These tissues that grow on the eye are "mis-programmed" cells (sometimes tooth or nail cells instead of eye cells).

The only treatment for MWS is only symptomatic, with multidisciplinary management

The main diagnostic tools for evaluating FND are X-rays and CT-scans of the skull. These tools could display any possible intracranial pathology in FND. For example, CT can be used to reveal widening of nasal bones. Diagnostics are mainly used before reconstructive surgery, for proper planning and preparation.

Prenatally, various features of FND (such as hypertelorism) can be recognized using ultrasound techniques. However, only three cases of FND have been diagnosed based on a prenatal ultrasound.

Other conditions may also show symptoms of FND. For example, there are other syndromes that also represent with hypertelorism. Furthermore, disorders like an intracranial cyst can affect the frontonasal region, which can lead to symptoms similar to FND. Therefore, other options should always be considered in the differential diagnosis.

In France, Aymé, "et al." (1989) estimated the prevalence of Fryns syndrome to be 0.7 per 10,000 births based on the diagnosis of 6 cases in a series of 112,276 consecutive births (live births and perinatal deaths).

The brain is usually grossly abnormal in outline when someone is diagnosed with Miller–Dieker syndrome. Only a few shallow sulci and shallow Sylvian fissures are seen; this takes on an hourglass or figure-8 appearance on the axial imaging. The thickness and measurement for a person without MDS is 3–4 mm. With MDS, a person's cortex is measured at 12–20 mm.

Diagnosis commonly occurs later in childhood and often occurs incidentally in asymptomatic patients or as a cause of visual impairment. The first symptoms are commonly found during routine vision screenings.

A number of examinations can be used to determine the extent of the syndrome and its severity. Fluorescein angiography is quite useful in diagnosing the disease, and the use of ultrasonography and optical coherence tomography (OCT) are helpful in confirming the disease. Neuro-ophthalmic examinations reveal pupillary defects (see Marcus Gunn Pupil). Funduscopic examinations, examinations of the fundus of the eye, allow detection of arteriovenous malformations. Neurological examinations can determine hemiparesis and paresthesias. Malformations in arteriovenous connections and irregular functions in the veins may be distinguished by fluorescein angiographies. Cerebral angiography examinations may expose AVMs in the cerebrum. MRIs are also used in imaging the brain and can allow visualization of the optic nerve and any possible atrophy. MRI, CT, and cerebral angiography are all useful for investigating the extent and location of any vascular lesions that are affecting the brain. This is helpful in determining the extent of the syndrome.