Urbach–Wiethe disease is typically diagnosed by its clinical dermatological manifestations, particularly the beaded papules on the eyelids. Doctors can also test the hyaline material with a periodic acid-Schiff (PAS) staining, as the material colors strongly for this stain.

Immunohistochemical skin labeling for antibodies for the ECM1 protein as labeling has been shown to be reduced in the skin of those affected by Urbach–Wiethe disease. Staining with anti-type IV collagen antibodies or anti-type VII collagen antibodies reveals bright, thick bands at the dermoepidermal junction.

Non-contrast CT scans can image calcifications, but this is not typically used as a means of diagnosing the disease. This is partly due to the fact that not all Urbach-Wiethe patients exhibit calcifications, but also because similar lesions can be formed from other diseases such as herpes simplex and encephalitis. The discovery of mutations within the ECM1 gene has allowed the use of genetic testing to confirm initial clinical diagnoses of Urbach–Wiethe disease. It also allows doctors to better distinguish between Urbach–Wiethe disease and other similar diseases not caused by mutations in ECM1.

Amniocentesis or chorionic villus sampling can be used to screen for the disease before birth. After birth, urine tests, along with blood tests and skin biopsies can be used to diagnose Schindler disease. Genetic testing is also always an option, since different forms of Schindler disease have been mapped to the same gene on chromosome 22; though different changes (mutations) of this gene are responsible for the infantile- and adult-onset forms of the disease.

Infants with Schindler disease tend to die within 4 years of birth, therefore, treatment for this form of the disease is mostly palliative. However, Type II Schindler disease, with its late onset of symptoms, is not characterized by neurological degeneration. There is no known cure for Schindler disease, but bone marrow transplants have been trialed, as they have been successful in curing other glycoprotein disorders.

Urbach–Wiethe disease is typically not a life-threatening condition. The life expectancy of these patients is normal as long as the potential side effects of thickening mucosa, such as respiratory obstruction, are properly addressed. Although this may require a tracheostomy or carbon dioxide laser surgery, such steps can help ensure that individuals with Urbach–Wiethe disease are able to live a full life. Oral dimethyl sulfoxide (DMSO) has been shown to reduce skin lesions, helping to minimize discomfort for these individuals.

Fabry disease is suspected based on the individual's clinical presentation, and can be diagnosed by an enzyme assay (usually done on leukocytes) to measure the level of alpha-galactosidase activity. An enzyme assay is not reliable for the diagnosis of disease in females due to the random nature of X-inactivation. Molecular genetic analysis of the "GLA" gene is the most accurate method of diagnosis in females, particularly if the mutations have already been identified in male family members. Many disease-causing mutations have been noted. Kidney biopsy may also be suggestive of Fabry disease if excessive lipid buildup is noted. Pediatricians, as well as internists, commonly misdiagnose Fabry disease.

The disease may be diagnosed by its characteristic grouping of certain cells (multinucleated globoid cells), nerve demyelination and degeneration, and destruction of brain cells. Special stains for myelin (e.g.; luxol fast blue) may be used to aid diagnosis.

The detection of tumours specific to VHL disease is important in the disease's diagnosis. In individuals with a family history of VHL disease, one hemangioblastoma, pheochromocytoma or renal cell carcinoma may be sufficient to make a diagnosis. As all the tumours associated with VHL disease can be found sporadically, at least two tumours must be identified to diagnose VHL disease in a person without a family history.

Genetic diagnosis is also useful in VHL disease diagnosis. In hereditary VHL, disease techniques such as southern blotting and gene sequencing can be used to analyse DNA and identify mutations. These tests can be used to screen family members of those afflicted with VHL disease; "de novo" cases that produce genetic mosaicism are more difficult to detect because mutations are not found in the white blood cells that are used for genetic analysis.

Microlissencephaly can be diagnosed by prenatal MRI. MRI is better than ultrasound when it comes to detecting microlissencephaly or MSGP prenatally.

The ideal time for proper prenatal diagnosis is between the 34th and 35th gestational week which is the time when the secondary gyration normally terminates. In microlissencephaly cases, the primary sulci would be unusually wide and flat while secondary sulci would be missing.

At birth, lissencephaly with a head circumference of less than minus three standard deviations (< –3 SD) is considered microlissencephaly.

Although genetic diagnosis in patients with MLIS is challenging, exome sequencing has been suggested to be a powerful diagnostic tool.

Microlissencephaly is considered a more severe form than microcephaly with simplified gyral pattern. Microlissencephaly is characterized by a smooth cortical surface (absent sulci and gyri) with a thickened cortex (> 3 mm) and is usually associated with other congenital anomalies. Microcephaly with a simplified gyral pattern has too few sulci and normal cortical thickness (3 mm) and is usually an isolated anomaly.

It is associated with LAMP2. The status of this condition as a GSD has been disputed.

Danon disease was characterized by Moris Danon in 1981. Dr. Danon first described the disease in 2 boys with heart and skeletal muscle disease (muscle weakness), and intellectual disability.

The first case of Danon disease reported in the Middle East was a family diagnosed in the eastern region of United Arab Emirates with a new "LAMP2" mutation; discovered by the Egyptian cardiologist Dr. Mahmoud Ramadan the associate professor of Cardiology in Mansoura University (Egypt) after doing genetic analysis for all the family members in Bergamo, Italy where 6 males were diagnosed as Danon disease patients and 5 female were diagnosed as carriers; as published in "Al-Bayan" newspaper in 20 February 2016 making this family the largest one with patients and carriers of Danon disease.

Danon Disease has overlapping symptoms with another rare genetic condition called 'Pompe' disease. Microscopically, muscles from Danon Disease patients appear similar to muscles from Pompe disease patients. However, intellectual disability is rarely, if ever, a symptom of Pompe disease. Negative enzymatic or molecular genetic testing for Pompe disease can help rule out this disorder as a differential diagnosis.

The majority of patients is initially screened by enzyme assay, which is the most efficient method to arrive at a definitive diagnosis. In some families where the disease-causing mutations are known and in certain genetic isolates, mutation analysis may be performed. In addition, after a diagnosis is made by biochemical means, mutation analysis may be performed for certain disorders.

The twins require the use of wheelchairs for mobility and are unable to speak without the assistance of electronic speaking aids. They experience persistent and painful muscle spasms which are worsened by emotional distress. They are currently living with their parents, with the assistance of hospice workers. Doctors continue to administer tests to the twins in search of a treatment.

In infantile Krabbe disease, death usually occurs in early childhood. A 2011 study found 1, 2, 3 year survival rates of 60%, 26%, and 14%, respectively. A few survived for longer and one was still alive at age 13. Patients with late-onset Krabbe disease tend to have a slower progression of the disease and live significantly longer.

Morbidity and mortality range from both extremes as the significance correlate with the underlying systemic disease.

There seems to be beneficial responses to clindamycin therapy as the lesions regress. This leads to the hypothesis that microorganisms may be playing a role in the initial stages of Kyrle disease.

A family with Kyrle disease were examined which their skin lesions were benign. However, when three of the young adult members were closely examined, they had posterior subcapsular cataracts and two of those three developed multiple tiny yellow-brown anterior stromal corneal opacities. In order to determine if there is any correlation between Kyrle disease and the ocular observations, more cases of Kyrle disease are to be analyzed.

All in all, since Kyrle disease is relatively rare, more cases need to be studied and analyzed in order to understand the underlying pathogenesis and to improve the management of the disease.

This disease is more common in women and an association with the gene FLT4 has been described. FLT4 codes for VEGFR-3, which is implicated in development of the lymphatic system.

Milroy's disease is also known as primary or hereditary lymphedema type 1A or early onset lymphedema.

It is a very rare disease with only about 200 cases reported in the medical literature. Milroy's disease is an autosomal dominant condition caused by a mutation in the FLT4 gene which encodes of the vascular endothelial growth factor receptor 3 (VEGFR-3) gene located on the long arm (q) on chromosome 5 (5q35.3).

In contrast to Milroy's disease (early onset lymphedema type 1A,) which typically has its onset of swelling and edema at birth or during early infancy, hereditary lymphedema type II, known as Meige disease, has its onset around the time of puberty. Meige disease is also an autosomal dominant disease. It has been linked to a mutations in the ‘forkhead’ family transcription factor (FOXC2) gene located on the long arm of chromosome 16 (16q24.3). About 2000 cases have been identified. A third type of hereditary lymphedema, that has an onset after the age of 35 is known as lymph-edema tarda.

There is no way to reverse VHL mutations, but early recognition and treatment of specific manifestations of VHL can substantially decrease complications and improve quality of life. For this reason, individuals with VHL disease are usually screened routinely for retinal angiomas, CNS hemangioblastomas, clear-cell renal carcinomas and pheochromocytomas. CNS hemangioblastomas are usually surgically removed if they are symptomatic. Photocoagulation and cryotherapy are usually used for the treatment of symptomatic retinal angiomas, although anti-angiogenic treatments may also be an option. Renal tumours may be removed by a partial nephrectomy or other techniques such as radiofrequency ablation.

There are three types of Sandhoff disease: classic infantile, juvenile, and adult late onset. Each form is classified by the severity of the symptoms as well as the age at which the patient shows these symptoms.

- Classic infantile form of the disease is classified by the development of symptoms anywhere from 2 months to 9 months of age. It is the most severe of all of the forms and will lead to death before the patient reaches the age of three. This is the most common and severe form of Sandhoff disease. Infants with this disorder typically appear normal until the age of 3 to 6 months, when development slows and muscles used for movement weaken. Affected infants lose motor skills such as turning over, sitting, and crawling. As the disease progresses, infants develop seizures, vision and hearing loss, dementia, and paralysis. An eye abnormality called a cherry-red spot, which can be identified with an eye examination, is characteristic of this disorder. Some infants with Sandhoff disease may have enlarged organs (organomegaly) or bone abnormalities. Children with the severe form of this disorder usually live only into early childhood.

- Juvenile form of the disease shows symptoms starting at age 3 ranging to age 10 and, although the child usually dies by the time they are 15, it is possible for them to live longer if they are under constant care. Symptoms include autism, ataxia, motor skills regression, spacticity, and learning disorders.

- Adult onset form of the disease is classified by its occurrence in older individuals and has an effect on the motor function of these individuals. It is not yet known if Sandhoff disease will cause these individuals to have a decrease in their life span.

Juvenile and adult onset forms of Sandhoff disease are very rare. Signs and symptoms can begin in childhood, adolescence, or adulthood and are usually milder than those seen with the infantile form of Sandhoff disease. As in the infantile form, mental abilities and coordination are affected. Characteristic features include muscle weakness, loss of muscle coordination (ataxia) and other problems with movement, speech problems, and mental illness. These signs and symptoms vary widely among people with late-onset forms of Sandhoff disease.

Milroy's disease (MD) is a familial disease characterized by lymphedema, commonly in the legs, caused by congenital abnormalities in the lymphatic system. Disruption of the normal drainage of lymph leads to fluid accumulation and hypertrophy of soft tissues. It is also known as Milroy disease, Nonne-Milroy-Meige syndrome and hereditary lymphedema.

It was named by Sir William Osler for William Milroy, a Canadian physician, who described a case in 1892, though it was first described by Rudolf Virchow in 1863.

Life expectancy with Fabry disease for males was 58.2 years, compared with 74.7 years in the general population, and for females 75.4 years compared with 80.0 years in the general population, according to registry data from 2001 to 2008. The most common cause of death was cardiovascular disease, and most of those had received kidney replacements.

Sandhoff disease can be detected through the following procedures (before it is apparent through physical examination): a biopsy removing a sample of tissue from the liver, genetic testing, molecular analysis of cells and tissues (to determine the presence of a genetic metabolic disorder), enzyme assay, and occasionally a urinalysis to determine if the above-noted compounds are abnormally stored within the body. For a child to suffer from this disease, both parents must be carriers, and both must transmit the mutation to the child. Thus, even in the case where both parents have the mutation, there is only a 25 percent chance their child will inherit the condition. Frequently, parents are given the opportunity to have a DNA screening if they are at high risk, to determine their carrier status before they have children. However, it is also highly recommended to undergo testing even for those parents who do not have a family history of Sandhoff disease. Over 95% of the families that have children with Sandhoff disease had no known prior family history of the condition, as the mutation in the HEXB gene is "silent," or recessive, and often passed undetected from one generation to the next Naturally, if an individual carries the mutation, he or she has a risk of transmitting it to the unborn child. Genetic counseling is recommended for those who have the mutation.

The most well known laboratory to perform the blood tests is through Lysosomal Diseases Testing Laboratory, Jefferson University with Dr. Wenger. Dr. Wenger’s laboratory does testing for all lysosomal diseases including Sandhoff and Tay-Sachs. They test for build-up of certain toxins in the body as well as a low count of enzymes.

It is possible for parents who are about to have a child or had a child with Sandhoff Disease can have a PGD or PEGD. PEGD is pre-embryonic genetic diagnosis for the parents that would not benefit from a pre-implantation genetic diagnosis because of their religion or negative attitude for the discarding of embryos. PEGD sequences the genome of the embryo to be produced by two parents if they were to conceive a child. If the family has a history of Sandhoff disease it is recommended they have their genome sequenced to ensure they are not carriers or to sequence the genome of their child.

The symptoms of LSD vary, depending on the particular disorder and other variables such as the age of onset, and can be mild to severe. They can include developmental delay, movement disorders, seizures, dementia, deafness, and/or blindness. Some people with LSDhave enlarged livers (hepatomegaly) and enlarged spleens (splenomegaly), pulmonary and cardiac problems, and bones that grow abnormally.

Lissencephaly 2, more commonly called Norman–Roberts syndrome, is a rare form of microlissencephaly caused by a mutation in the RELN gene.A small number of cases have been described. The syndrome was first reported by Margaret Grace Norman and M. Roberts et al. in 1976.

Lack of reelin prevents normal layering of the cerebral cortex and disrupts cognitive development. Patients have cerebellar hypoplasia and suffer from congenital lymphedema and hypotonia. The disorder is also associated with myopia, nystagmus and generalized seizures.

Norman–Roberts syndrome is one of two known disorders caused by a disruption of the reelin-signaling pathway. The other is VLDLR-associated cerebellar hypoplasia, which is caused by a mutation in the gene coding for one of the reelin receptors, VLDLR.

Disruption of the RELN gene in human patients is analogous to the malfunctioning RELN gene in the reeler mouse.

It is important to include that the lesion is associated with another cancer. A biopsy will establish the diagnosis. The histology of the lesion is the same as for Paget's disease of the breast.