The diagnosis of Mulibrey nanism can be done via genetic testing, as well as by the physical characteristics (signs/symptoms) displayed by the individual.

Ultrasound remains as one of the only effective ways of prenatally diagnosing Larsen syndrome. Prenatal diagnosis is extremely important, as it can help families prepare for the arrival of an infant with several defects. Ultrasound can capture prenatal images of multiple joint dislocations, abnormal positioning of legs and knees, depressed nasal bridge, prominent forehead, and club feet. These symptoms are all associated with Larsen syndrome, so they can be used to confirm that a fetus has the disorder.

This includes Ataxia-telegiectasia, Chédiak-Higashi syndrome, DiGeorge syndrome, Griscelli syndrome and Marinesco-Sjogren syndrome.

The diagnostic work up usually includes and MRI of the brain, an EEG, ophthalmic examination and a cardiac ECHO.

Muscle biopsy - which is not commonly done - may show storage of abnormal material and secondary mitochondrial abnormalities in skeletal muscle. Other features that may be seen on muscle biopsy include variability in fibre size, increase in internal and centralized nuclei, type 1 fibre hypotrophy with normally sized type 2 fibres, increased glycogen storage and variable vacuoles on light microscopy

The diagnosis is confirmed by sequencing of the EPG5.

Kaufman oculocerebrofacial syndrome differential diagnosis consists of:

The diagnosis of Kaufman oculocerebrofacial syndrome can be achieved via molecular testing approaches. Additionally to ascertain if the individual has the condition:

- Growth assessment

- Thyroid function evaluation

- Kidney ultrasound

- Echocardiogram

Treatment usually involves plastic and reconstructive surgery. Surgery may be needed to correct undescended testes or hernias.

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

Tetra-amelia syndrome has been reported in only a few families worldwide.

According to a 2011 study by Bermejo-Sanchez, amelia – that is, the lacking of one or more limbs – occurs in roughly 1 out of every 71,000 pregnancies.

In terms of treatment/management for those with Mulibrey nanism should have routine medical follow-ups, additionally the following can be done:

- Growth hormone treatment

- Regular pelvic exams

- Pericardiectomy

While Larsen syndrome can be lethal if untreated, the prognosis is relatively good if individuals are treated with orthopedic surgery, physical therapy, and other procedures used to treat the symptoms linked with Larsen syndrome.

The differential diagnosis for this condition consists of acquired immune deficiency syndrome and severe combined immunodeficiency syndrome

The diagnosis of Nezelof syndrome will indicate a deficiency of T-cells, additionally in ascertaining the condition the following is done:

The recurrence of DOOR in siblings and the finding of DOOR syndrome in a few families with consanguinity suggest that the condition is an autosomal recessive genetic condition. Mutations in TBC1D24 have been identified in 9 families.

Due to the wide range of genetic disorders that are presently known, diagnosis of a genetic disorder is widely varied and dependent of the disorder. Most genetic disorders are diagnosed at birth or during early childhood, however some, such as Huntington's disease, can escape detection until the patient is well into adulthood.

The basic aspects of a genetic disorder rests on the inheritance of genetic material. With an in depth family history, it is possible to anticipate possible disorders in children which direct medical professionals to specific tests depending on the disorder and allow parents the chance to prepare for potential lifestyle changes, anticipate the possibility of stillbirth, or contemplate termination. Prenatal diagnosis can detect the presence of characteristic abnormalities in fetal development through ultrasound, or detect the presence of characteristic substances via invasive procedures which involve inserting probes or needles into the uterus such as in amniocentesis.

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.

Many features of gerodermia osteodysplastica (GO) and another autosomal recessive form of cutis laxa, wrinkly skin syndrome (WSS, ""), are similar to such an extent that both disorders were believed to be variable phenotypes of a single disorder.

Several delineating factors, however, suggest that gerodermia osteodysplastica and wrinkly skin syndrome are distinct entities, but share the same clinic spectrum.

While the prevailing feature of wrinkly, loose skin is more localized with GO, it is usually systemic, yet eases in severity with age during the course of WSS. Also, as the fontanelles ("soft spots") are usually normal on the heads of infants with GO, they are often enlarged in WSS infants.

While WSS is associated with mutations of genes on chromosomes 2, 5, 7, 11 and 14; GO has been linked to mutations in the protein GORAB. A serum sialotransferrin type 2 pattern, also observed with WSS, is not present in GO patients.

But perhaps the most notable feature, differentiating GO from WSS and similar cutis laxa disorders, is the age-specific metaphyseal peg sometimes found in GO-affected long bone, near the knee. Not appearing until around age 4–5, then disappearing by physeal closure, this oddity of bone is thought to represent a specific genetic marker unique to GO and its effects on bone development.

The syndrome is named after Turkish (Asim Cenani) and German (Widukind Lenz) medical geneticists.

Mäkelä-Bengs et al. (1997,1998) performed a genome-wide screening and linkage analysis and assigned the LCCS locus to a defined region of 9q34.

Elevated IgE is the hallmark of HIES. An IgE level greater than 2,000 IU/mL is often considered diagnostic. However, patients younger than 6 months of age may have very low to non-detectable IgE levels. Eosinophilia is also a common finding with greater than 90% of patients having eosinophil elevations greater than two standard deviations above the normal mean. Genetic testing is available for "STAT3" (Job's Syndrome), "DOCK8 (DOCK8 Immunodeficiency or DIDS)", "PGM3" (PGM3 deficiency), "SPINK5" (Netherton Syndrome - NTS), and "TYK2" genetic defects.

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.

Cenani–Lenz syndactylism, also known as Cenani–Lenz syndrome or Cenani–syndactylism, is an autosomal recessive congenital malformation syndrome involving both upper and lower extremities.

RL syndrome is characterized by renal dysplasia, growth retardation, phocomelia or mesomelia, radiohumeral fusion (joining of radius and humerus), rib abnormalities, anomalies of the external genitalia and potter-like facies among many others.

Not all of the DOOR symptoms are consistently present. They can vary in severity, and additional features can be noted in individuals affected by DOOR syndrome.

Some of these additional features are:

- Polyhydramnios (increased amniotic fluid during pregnancy) and increased nuchal fold during pregnancy

- Specific facial features such as a large nose

- Severe and sometimes refractory seizures, abnormalities on the magnetic resonance imaging of the brain

- Increased 2-oxoglutaric acid in the blood and urine - this compound is made or used by several enzymes

- Finger-like thumbs

- Visual impairment

- Peripheral neuropathy (nerves conducting sensation from extremities to the brain) and insensivity to pain

Intellectual impairment is present in all reported cases, but the severity can vary widely. The prognosis in terms of survival also varies greatly from early childhood till adulthood.

Most patients with hyper IgE syndrome are treated with long-term antibiotic therapy to prevent staphylococcal infections. Good skin care is also important in patients with hyper IgE syndrome. High-dose intravenous gamma-globulin has also been suggested for the treatment of severe eczema in patients with HIES and atopic dermatitis.