There are very few ways to test a patient for HGF. Currently, the most common way to diagnose a patient is by means of a physical evaluation. The physician can make a physical evaluation of the patient and send them to a dentist or better yet a specialist like a periodontist to evaluate signs of gingival overgrowth, quality of gingiva, inflammation, mechanical difficulties of the mouth, tooth conditions, and any sort of discomfort.

Aside from obvious physical symptoms seen in a physical evaluation, molecular tests can be run to check if there is a mutation in the SOS1 gene to confirm the diagnosis. If there is indeed a mutation in this gene coupled with the typical physical symptoms, then it is quite probable that a patient suffers from this disease. Also, looking at family history is also becoming more prominent in aiding to diagnose the patient. Otherwise, researchers are working to find new and better ways to test for the presence of HGF.

Because this genetic anomaly is genetically linked, genetic counseling may be the only way to decrease occurrences of Cherubism. The lack of severe symptoms in the parents may be the cause of failure in recognizing the disorder. The optimal time to be tested for mutations is prior to having children. The disorder results from a genetic mutation, and this gene has been found to spontaneously mutate. Therefore, there may be no prevention techniques available.

The chemical imbalance is usually diagnosed when dental abnormalities are found. These abnormalities include premature deciduous teeth and abnormal growth of permanent teeth due to displacement by cysts and lesions. The only definite way to correctly diagnose the condition is by sequence analysis of the SH3BP2 gene. The gene has been found to have missense mutation in exon 9. Initial study of the patient is usually conducted using x-ray and CT scans. Neurofibromatosis may resemble Cherubism and may accompany the condition. Genetic testing is the final diagnosis tool.

Since this condition is generally agreed upon to be hereditary, nothing can be done to prevent HGF. However, in some cases where it can develop as a result of rare multi-system syndromes, such as: Zimmerman-Laband, Jones, Ramon Syndrome, Rutherford Syndrome, Juvenile Hyaline Fibromatosis, Systemic Infantile Hyalinosis, and Mannosidosis, it is best for one to simply monitors the possible progression for HGF with regular dental check-ups.

If the patient's disease is treated by means of surgery, it is recommended that the patient undergoes post-surgical therapies for maintenance and periodic monitoring of gums for the sake of the possibility of re-occurrence of HGF.

While there is no cure for BGS, symptoms can be treated as they arise. Surgery shortly after birth can repair craniosynostosis, as well as defects in the hand to create a functional grasp. There are risks associated with untreated craniosynostosis, therefore surgery is often needed to separate and reshape the bones. Since patients with a RECQL4 mutation may be at an increased risk of developing cancer, surveillance is recommended.

No pathognomonic clinical signs for TSC complex are seen. Many signs are present in individuals who are healthy (although rarely), or who have another disease. In order to meet diagnostic criteria for TSC complex, an individual must either have: 1) Two or more major criteria; or 2) One major criterion along with two or more minor criteria.

In infants, the first clue is often the presence of seizures, delayed development, or white patches on the skin. A full clinical diagnosis involves:

- Taking a personal and family history

- Examining the skin under a Wood's lamp (hypomelanotic macules), the fingers and toes (ungual fibroma), the face (angiofibromas), and the mouth (dental pits and gingival fibromas)

- Cranial imaging with nonenhanced CT or, preferably, MRI (cortical tubers and subependymal nodules)

- Renal ultrasound (angiomyolipoma or cysts)

- An echocardiogram in infants (rhabdomyoma)

- Fundoscopy (retinal nodular hamartomas or achromic patch)

The various signs are then marked against the diagnostic criteria to produce a level of diagnostic certainty:

- Definite – either two major features or one major feature plus two minor features

- Probable – one major plus one minor feature

- Suspect – either one major feature or two or more minor features

Due to the wide variety of mutations leading to TSC, no simple genetic tests are available to identify new cases, nor are any biochemical markers known for the gene defects. However, once a person has been clinically diagnosed, the genetic mutation can usually be found. The search is time-consuming and has a 15% failure rate, which is thought to be due to somatic mosaicism. If successful, this information can be used to identify affected family members, including prenatal diagnosis. , preimplantation diagnosis is not widely available.

There is currently no cure for GAPO syndrome, but some options are available to reduce the symptoms. Nearsightedness, which affects some sufferers of the disease, can be treated by corrective lenses. Unfortunately, optic atrophy as a result of degradation of the optic nerve (common with GAPO syndrome) cannot be corrected. Corticosteroids have been proposed as a treatment for optic nerve atrophy, but their effectiveness is disputed, and no steroid based treatments are currently available.

This disorder is caused by an abnormality of the TBCE gene, the locus for which is on Chromosome 1q42.3. The locus is a 230 kb region of gene with identified deletions and mutations in affected individuals. There are rare cases of the disorder not being due to a TBCE gene abnormality.

Researchers are also investigating the genetic similarities between Dubowitz Syndrome and Smith-Lemli-Opitz syndrome (SLOS). Patients with SLOS and Dubowitz syndromes experience many of the same abnormalities, and the two disorders are hypothesized to be linked. A characteristic of SLOS is a low cholesterol level and a high 7-dehydrocholesterol level. Cholesterol is essential for several key functions of the body, including cell membrane structure, embryogenesis, and steroid and sex hormone synthesis. Impaired cholesterol biosynthesis or transport possibly accounts for most of the symptoms of both SLOS and Dubowitz. Although only a few patients with Dubowitz Syndrome have been identified with altered cholesterol levels, researchers are exploring whether Dubowitz Syndrome, like SLOS, carries a link to a defect in the cholesterol biosynthetic pathway.

The exact biochemical pathology of the disease is still under research because of the low prevalence of the disease and the wide array of symptoms associated with it. Several studies have focused on different aspects of the disease to try to find its exact cause and expression. One study examined the specific oral features in one patient. Another found abnormalities in the brain, such as corpus callosum dysgenesis, an underdeveloped anterior pituitary and a brain stalk with an ectopic neurohypophysis.

Other features include:

- Stunting

- Small hands and feet with long, tapering fingers and clinodactyly

- Dental anomalies in the form of malalignment and malocclusion

In another study of six patients, the patients were investigated further. They were found to have low levels of IGF-1 and markedly retarded bone age.

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

There is no known cure at the moment but there are several things that can be done to relieve the symptoms. Moisturising products are very helpful to minimize the scaling/cracking, and anti-infective treatments are useful when appropriate because the skin is very susceptible to infection. Extra protein in the diet during childhood is also beneficial, to replace that which is lost through the previously mentioned "leaky" skin.

Steroid and retinoid products have been proven ineffective against Netherton syndrome, and may in fact make things worse for the affected individual.

Intravenous immunoglobulin has become established as the treatment of choice in Netherton's syndrome. This therapy reduces infection; enables improvement and even resolution of the skin and hair abnormalities, and dramatically improves quality of life of the patients; although exactly how it achieves this is not known. Given this; it is possible that the reason Netherton's usually is not very severe at or shortly after birth is due to a protective effect of maternal antibodies; which cross the placenta but wane by four to six months.

Symptoms include gingival fibromatosis, associated with hypoplasia of the distal phalanges, nail dysplasia, joint hypermobility, and sometimes hepatosplenomegaly. The nose and pinnae are usually large and poorly developed, which gives the individuals with the syndrome abnormal facial characteristics. Mental retardation may also occur. Both males and females are equally affected. Gingival fibromatosis is usually present at birth or appears short after. The term Zimmermann–Laband was coined by Carl Jacob Witkop in 1971.

Zimmermann–Laband syndrome (ZLS), also known as Laband–Zimmermann syndrome, and Laband's syndrome, is an extremely rare autosomal dominant congenital disorder.

One known cause of hypertrichosis cubiti is Wiedemann-Steiner syndrome.

Juvenile hyaline fibromatosis (also known as "Fibromatosis hyalinica multiplex juvenilis," "Murray–Puretic–Drescher syndrome") is a very rare, autosomal recessive disease due to mutations in capillary morphogenesis protein-2 (CMG-2 gene). It occurs from early childhood to adulthood, and presents as slow-growing, pearly white or skin-colored dermal or subcutaneous papules or nodules on the face, scalp, and back, which may be confused clinically with neurofibromatosis.

Dubowitz syndrome is a rare genetic disorder characterized by microcephaly, stunted growth, and a receding chin. Symptoms vary among patients, but other characteristics include a soft, high-pitched voice; partial webbing of the fingers and toes; palate deformations; genital abnormalities; language difficulties; and an aversion to crowds. The pathogenesis of the disease is yet to be identified, and no medical tests can definitively diagnose the disease. The primary method of diagnosis is to identify facial phenotypes. Since it was first described in 1965 by English physician Victor Dubowitz, over 140 cases have been reported worldwide. Although the majority of cases have been reported from the United States, Germany, and Russia, the disorder appears to affect both genders and all ethnicities equally.

Hypertrichosis cubiti (also known as "hairy elbow syndrome") is a cutaneous condition characterized by multiple terminal hairs on both elbows in children.

Baller–Gerold syndrome is caused by a mutation in the RECQL4 gene found on chromosome 8p24. Molecular genetic tests used to identify mutations in the RECQL4 gene include targeted variant analysis and sequence analysis of the entire coding region of the gene. These methods look for changes in the sequence encoding RECQL4, as having a deleterious mutation in the gene will change the protein and disrupt its usual function. RECQL4 is a gene that encodes a DNA helicase in the RecQ helicase family. Helicases are involved with unwinding DNA in preparation for DNA replication and repair.

Baller–Gerold syndrome is inherited in an autosomal recessive pattern of inheritance, meaning that an affected child gets one mutant allele from each parent to produce the syndrome. A carrier is someone who has one mutant allele but does not does have any symptoms. If both parents are carriers, there is a 25% chance the child will have BGS. There is also a 50% chance the child will have one mutant copy (be a carrier) and be asymptomatic and a 25% chance the child will be asymptomatic and not a carrier. In order for someone to have BGS, they need to have two mutant copies of the gene. Adults may pursue genetic counselling to understand the syndrome, as well as the risks and choices regarding family planning.

X-linked hypertrichosis is a hereditary disorders characterized by generalized congenital hypertrichosis.

Cross–McKusick–Breen syndrome (also known as "Cross syndrome", "hypopigmentation and microphthalmia", and "oculocerebral-hypopigmentation syndrome") is an extremely rare disorder characterized by white skin, blond hair with yellow-gray metallic sheen, small eyes with cloudy corneas, jerky nystagmus, gingival fibromatosis and severe mental and physical retardation.

It was characterized in 1967.

Saal Greenstein syndrome is a very rare autosomal recessive genetic disorder characterized by stunted growth, short limbs, microcephaly, and an anomalous cleavage of the anterior chamber of the eye. The disorder is similar to Robinow syndrome except for anterior chamber anomalies and, in one case, hydrocephalus.

GAPO syndrome is a rare, autosomal recessive disorder that causes severe growth retardation, and has been observed fewer than 30 times before 2011. GAPO is an acronym that encompasses the predominant traits of the disorder: growth retardation, alopecia, pseudoanodontia (teeth failing to emerge from the gums), and worsening optic atrophy in some subjects. Other common symptoms include premature aging, large, prominent foreheads, and delayed bone aging. GAPO syndrome typically results in premature death around age 30-40, due to interstitial fibrosis and atherosclerosis.

Diagnosis of megalencephaly has changed over the years, however, with the development of more advanced equipment, physicians have been able to confirm the disorder with better accuracy. Usually, a physical exam is first performed when characteristics of megalencephaly have appeared. This typically occurs at birth or during early child development. A physician will then take head measurements in order to determine the circumference. This is known as the head circumference. Then a family background will be recorded in order to determine if there has been a history of megalencephaly in the family.

A neurological exam will then be performed using the technology of an MRI machine in order to confirm the diagnosis of megalencephaly. These imaging tests give detailed information regarding brain size, volume asymmetry and other irregular developments linked with MCAP, MPPH and hemimegalencephaly.

There is also a strong correlation of epilepsy and megalencephaly and this can aid doctors in their diagnosis.

If a diagnosis of megalencephaly is confirmed, the child is referred to a specialist who focuses on managing the symptoms and improving lifestyle. Since megalencephaly is usually presented with autism, the goal of treatment is to improve deficiencies associated with autistic causes. Additionally, since each patient has unique symptoms, there is no one specific treatment method and therefore is heavily reliant on symptoms associated with an individual.

TSC typically affects multiple organ systems and manifests differently in each patient and in different stages of the life course. Drug therapy, surgery, and other interventions can be effective in managing some of the manifestations and symptoms of TSC.

In the United States, the Food and Drug Administration has approved several drugs for managing some of the major manifestations of TSC. The antiepileptic medication vigabatrin was approved in 2009 for treatment of infantile spasms and was recommended as first-line therapy for infantile spasms in children with TSC by the 2012 International TSC Consensus Conference. Adrenocorticotropic hormone was approved in 2010 to treat infantile spasms. Everolimus was approved for treatment of TSC-related tumors in the brain (subependymal giant cell astrocytoma) in 2010 and in the kidneys (renal angiomyolipoma) in 2012. Everolimus also showed evidence of effectiveness at treating epilepsy in some people with TSC. In 2017, the European Commission approved everolimus for treatment of refractory partial-onset seizures associated with TSC.

Neurosurgical intervention may reduce the severity and frequency of seizures in TSC patients. Embolization and other surgical interventions can be used to treat renal angiomyolipoma with acute hemorrhage. Surgical treatments for symptoms of lymphangioleiomyomatosis (LAM) in adult TSC patients include pleurodesis to prevent pneumothorax and lung transplantation in the case of irreversible lung failure.

Other treatments that have been used to treat TSC manifestations and symptoms include a ketogenic diet for intractable epilepsy and pulmonary rehabilitation for LAM.