Different features of the dysostosis are significant. Radiological imaging helps confirm the diagnosis. During gestation (pregnancy), clavicular size can be calculated using available nomograms. Wormian bones can sometimes be observed in the skull.

Diagnosis of CCD spectrum disorder is established in an individual with typical clinical and radiographic findings and/or by the identification of a heterozygous pathogenic variant in RUNX2 (CBFA1).

PD diagnosis is based primarily on the presence and position of ulcers on the skin, as well as identifying particular protein markers in urine. To confirm the diagnosis, a blood test is required to measure prolidase activity.

Initially, the clinical presentation of SDS may appear similar to cystic fibrosis. However, CF can be excluded with a normal chloride in sweat test but faecal elastase as a marker of pancreatic function will be reduced. The variation, intermittent nature, and potential for long-term improvement of some clinical features make this syndrome difficult to diagnose. SDS may present with either malabsorption, or hematological problems. Rarely, SDS may present with skeletal defects, including severe rib cage abnormalities that lead to difficulty in breathing. Diagnosis is generally based on evidence of exocrine pancreatic dysfunction and neutropenia. Skeletal abnormalities and short stature are characteristics that can be used to support the diagnosis. The gene responsible for the disease has been identified and genetic testing is now available. Though useful in diagnostics, a genetic test does not surmount the need for careful clinical assessment and monitoring of all patients.

Figueroa and Pruzanksky classified HFM patients into three different types:

- Type I : Mild hypoplasia of the ramus , and the body of the mandible is slightly affected.

- Type II : The condyle and ramus are small, the head of the condyle is flattened , the glenoid fossa is absent , the condyle is hinged on a flat, often convex, infratemporal surface , the coronoid may be absent.

- Type III: The ramus is reduced to a thin lamina of bone or is completely absent. There is no evidence of a TMJ.

Diagnosis of Crouzon syndrome usually can occur at birth by assessing the signs and symptoms of the baby. Further analysis, including radiographs, magnetic resonance imaging (MRI) scans, genetic testing, X-rays and CT scans can be used to confirm the diagnosis of Crouzon syndrome.

A few techniques are used to confirm the diagnosis in TCS.

An orthopantomogram (OPG) is a panoramic dental X-ray of the upper and lower jaw. It shows a two-dimensional image from ear to ear. Particularly, OPG facilitates an accurate postoperative follow-up and monitoring of bone growth under a mono- or double-distractor treatment. Thereby, some TCS features could be seen on OPG, but better techniques are used to include the whole spectrum of TCS abnormalities instead of showing only the jaw abnormalities.

Another method of radiographic evaluation is taking an X-ray image of the whole head. The lateral cephalometric radiograph in TCS shows hypoplasia of the facial bones, like the malar bone, mandible, and the mastoid.

Finally, occipitomental radiographs are used to detect hypoplasia or discontinuity of the zygomatic arch.

A temporal-bone CT using thin slices makes it possible to diagnose the degree of stenosis and atresia of the external auditory canal, the status of the middle ear cavity, the absent or dysplastic and rudimentary ossicles, or inner ear abnormalities such as a deficient cochlea. Two- and three-dimensional CT reconstructions with VRT and bone and skin-surfacing are helpful for more accurate staging and the three-dimensional planning of mandibular and external ear reconstructive surgery.

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.

Brain MRI shows vermis atrophy or hypoplasic. Cerebral and cerebellar atrophy with white matter changes in some cases.

Depending upon the treatment required, it is sometimes most appropriate to wait until later in life for a surgical remedy – the childhood growth of the face may highlight or increase the symptoms. When surgery is required, particularly when there is a severe disfiguration of the jaw, it is common to use a rib graft to help correct the shape.

According to literature, HFM patients can be treated with various treatment options such functional therapy with an appliance, distraction osteogenesis, or costochondral graft. The treatment is based on the type of severity for these patients. According to Pruzanksky's classification, if the patient has moderate to severe symptoms, then surgery is preferred. If patient has mild symptoms, then a functional appliance is generally used.

Patients can also benefit from a Bone Anchored Hearing Aid (BAHA).

No treatment is available for most of these disorders. Mannose supplementation relieves the symptoms in PMI-CDG (CDG-Ib) for the most part, even though the hepatic fibrosis may persist. Fucose supplementation has had a partial effect on some SLC35C1-CDG (CDG-IIc or LAD-II) patients.

The treatment for Morquio syndrome consists of prenatal identification and of enzyme replacement therapy. On 12 February 2014, the US Food and Drug Administration approved the drug elosulfase alfa (Vimizim) for treating the disease.

There is a deficiency of malate in patients because fumarase enzyme can't convert fumarate into it therefore treatment is with oral malic acid which will allow the krebs cycle to continue, and eventually make ATP.

There is no causative / curative therapy. Symptomatic medical treatments are focussing on symptoms caused by orthopaedic, dental or cardiac problems. Regarding perioperative / anesthesiological management, recommendations for medical professionals are published at OrphanAnesthesia.

Around 5 years of age, surgical correction may be necessary to prevent any worsening of the deformity. If the mother has dysplasia, caesarian delivery may be necessary. Craniofacial surgery may be necessary to correct skull defects. Coxa vara is treated by corrective femoral osteotomies. If there is brachial plexus irritation with pain and numbness, excision of the clavicular fragments can be performed to decompress it. In case of open fontanelle, appropriate headgear may be advised by the orthopedist for protection from injury.

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.

No curative treatment is available for prolidase deficiency at this time, although palliative treatment is possible to some extent.

The latter mainly focuses on treating the skin lesions through standard methods and stalling collagen degradation (or boosting prolidase performance, where possible), so as to keep the intracellular dipeptide levels low and give the cells time to resynthesise or absorb what proline they cannot recycle so as to be able to rebuild what collagen "does" degrade. Patients can be treated orally with ascorbate (a.k.a. vitamin C, a cofactor of prolyl hydroxylase, an enzyme that hydroxylates proline, increasing collagen stability), manganese (a cofactor of prolidase), suppression of collagenase (a collagen degrading enzyme), and local applications of ointments that contain L-glycine and L-proline. The response to the treatment is inconsistent between affected individuals.

A therapeutic approach based on enzyme replacement (administering functional prolidase) is under consideration.

Due to the weakened immune response in PD cases, it is also of paramount importance to keep any infections under control, often with heavy antibiotics.

The disorder was first described in 1969 by the German-American Human Geneticist Meinhard Robinow (1909–1997), along with physicians Frederic N. Silverman and Hugo D. Smith, in the "American Journal of Diseases of Children". By 2002, over 100 cases had been documented and introduced into medical literature.

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.

Sabinas brittle hair syndrome is inherited as an autosomal recessive genetic trait.

In a study by Howell et al. patients were located and studied by means of complete histories and physical examinations, analyses of serum trace metals, ceruloplasmin concentration, urine and serum amino acids, and routine metabolic urine screens. In addition, serum and urine luteinizing hormone (LH) and follicle-stimulating hormone (FSH) values were determined, and were interpreted in conjunction with total plasma estrogen, estradiol, and testosterone levels. Close examination demonstrated the scalp hairs were very brittle, coarse, wiry in texture, and broke off quite easily with mechanical trauma such as combing and brushing. Some hairs could be visualized in their follicles, which were broken off at the skin line. Most patients had accompanying hyperkeratosis (thickening of the skin) of moderate degree on exposed surfaces. Maxillary hypoplasia (midfacial retrusion) was significant in many patients. The brittle, short hair, reduced eyelashes, crowded teeth, and dull appearance created a characteristic facial appearance. Post-pubertal patients had development of secondary sexual characteristics consistent with their age, except for sparse pubic escutcheons. All cases studied demonstrated some degree of mental deficiency; I.Q.'s ranged between 50–60. A deficiency in eye–hand coordination was also noted.

Pancreatic exocrine insufficiency may be treated through pancreatic enzyme supplementation, while severe skeletal abnormalities may require surgical intervention. Neutropenia may be treated with granulocyte-colony stimulating factor (GCSF) to boost peripheral neutrophil counts. However, there is ongoing and unresolved concern that this drug could contribute to the development of leukemia. Signs of progressive marrow failure may warrant bone marrow transplantation (BMT). This has been used successfully to treat hematological aspects of disease. However, SDS patients have an elevated occurrence of BMT-related adverse events, including graft-versus-host disease (GVHD) and toxicity relating to the pre-transplant conditioning regimen. In the long run, study of the gene that is mutated in SDS should improve understanding of the molecular basis of disease. This, in turn, may lead to novel therapeutic strategies, including gene therapy and other gene- or protein-based approaches.

PNP-deficiency is extremely rare. Only 33 patients with the disorder in the United States have been documented. In the United Kingdom only one child has been diagnosed with this disorder.

Each child is different and it entirely depends on which sutures are fused and how it is affecting the child as to how it is treated. Some children have severe breathing issues due to shallow mid face and may require a tracheostomy. All should be treated at a specialist centre. Cranio bands are not used in the UK.

Surgery is typically used to prevent the closure of sutures of the skull from damaging the brain's development. Without surgery, blindness and mental retardation are typical outcomes. Craniofacial surgery is a discipline of both plastic surgery and oral and maxillofacial surgery (OMFS) . To move the orbits forward, craniofacial surgeons expose the skull and orbits and reshape the bone. To treat the midface deficiency, craniofacial surgeons can move the lower orbit and midface bones forward. For jaw surgery, either plastic surgeons or OMFS surgeons can perform these operations.

Crouzon patients tend to have multiple sutures involved, most specifically bilateral coronal craniosynostoses, and either open vault surgery or strip craniectomy (if child is under 6 months) can be performed. In the later scenario, a helmet is worn for several months following surgery.

Once treated for the cranial vault symptoms, Crouzon patients generally go on to live a normal lifespan.

Genetic studies have linked the autosomal recessive form of the disorder to the "ROR2" gene on position 9 of the long arm of chromosome 9. The gene is responsible for aspects of bone and cartilage growth. This same gene is involved in causing autosomal dominant brachydactyly B.

The autosomal dominant form has been linked to three genes - WNT5A, Segment polarity protein dishevelled homolog DVL-1 (DVL1) and Segment polarity protein dishevelled homolog DVL-3 (DVL3). This form is often caused by new mutations and is generally less severe then the recessive form. Two further genes have been linked to this disorder - Frizzled-2 (FZD2) and Nucleoredoxin (NXN gene). All of these genes belong to the same metabolic pathway - the WNT system. This system is involved in secretion for various compounds both in the fetus and in the adult.

A fetal ultrasound can offer prenatal diagnosis 19 weeks into pregnancy. However, the characteristics of a fetus suffering from the milder dominant form may not always be easy to differentiate from a more serious recessive case. Genetic counseling is an option given the availability of a family history.

The diagnosis of CTD is usually suspected based on the clinical presentation of mental retardation, abnormalities in cognitive and expressive speech, and developmental delay. Furthermore, a family history of X-linked intellectual disability, developmental coordination disorder, and seizures is strongly suggestive. Initial screening of CTD involves obtaining a urine sample and measuring the ratio of creatine to creatinine. If the ratio of creatine to creatinine is greater than 1.5, then the presence of CTD is highly likely. This is because a large ratio indicates a high amount of creatine in the urine. This, in turn, indicates inadequate transport of creatine into the brain and muscle. However, the urine screening test often fails in diagnosing heterozygous females. Studies have demonstrated that as a group heterozygous females have significantly decreased cerebral creatine concentration, but that individual heterozygous females often have normal creatine concentrations found in their urine. Therefore, urine screening tests are unreliable as a standard test for diagnosing CTD.

A more reliable and sophisticated manner of testing for cerebral creatine concentrations is through "in vivo" proton magnetic resonance spectroscopy (1H MRS). "In vivo" 1H MRS uses proton signals to determine the concentration of specific metabolites. This method of testing is more reliable because it provides a fairly accurate measurement of the amount of creatine inside the brain. Similar to urine testing, a drawback of using 1H MRS as a test for CTD is that the results of the test could be attributed to any of the cerebral creatine deficiencies. The most accurate and reliable method of testing for CTD is through DNA sequence analysis of the SLC6A8 gene. DNA analysis of SLC6A8 allows the identification of the location and type of mutation causing the cerebral creatine deficiency. Furthermore, DNA analysis of SLC6A8 is able to prove that a cerebral creatine deficiency is due to CTD and not GAMT or AGAT deficiency.