About ectodermal dysplasias

What is ectodermal dysplasias?

Johanson-Blizzard syndrome (JBS) is an extremely rare genetic disorder that affects multiple organ systems of the body. Many symptoms are present at birth (congenital) or early childhood. The spectrum of potential features and physical findings associated with JBS is wide and varied and can differ dramatically from one person to another. However, characteristic features include insufficient intestinal absorption (malabsorption) of fats and other nutrients due to abnormal development of the pancreas (pancreatic insufficiency); failure to grow and gain weight at the expected rate (failure to thrive) during the first years of life, contributing to short stature; abnormalities of permanent teeth; distinctive abnormalities of the skull and facial (craniofacial) region including a small "beak-shaped" nose; and/or varying degrees of intellectual disability. JBS is caused by mutations to the UBR1 gene. This genetic mutation is inherited as an autosomal recessive trait.

What are the symptoms for ectodermal dysplasias?

Abnormal hair symptom was found in the ectodermal dysplasias condition

Each of the nearly 100 EDs has its own set of clinical signs and symptoms. Commonly, the conditions will have one or more of the following associated findings:

  • Teeth: reduced number, abnormal shape or size
  • Hair: abnormal structure, sparse, slow-growing, often light-colored
  • Sweat glands: often reduced number and abnormal structure, leading to decreased sweat production and risk of elevated body temperature (hyperthermia)
  • Nails: toenails and fingernails can be absent, thin, thick, grooved
  • Cleft lip and/or palate, particularly in the TP63-related disorders
  • Limb abnormalities: split hand/foot, oligodactyly, syndactyly, digital duplication
  • Skin abnormalities: spotty hypoplasia with fat herniation, severe skin erosions, pigmentary abnormalities, etc
  • Ocular abnormalities: dry eye, corneal erosions/opacification, eyelid fusion, micropthalmia
  • Genitourinary abnormalities:  hydroureter, hydronephrosis, renal agenesis, micropenis, cryptorchidism, hypospadias
  • Growth failure (height and/or weight)

What are the causes for ectodermal dysplasias?

The molecular causes of these diverse conditions involve many genes and multiple developmental pathways that are necessary for normal formation, structure and function of the ectodermal derivatives. This classification scheme does not include all disorders that affect two or more ectodermal derivatives. Genetic alterations of ED-associated genes that affect only one derivative of the ectoderm would be considered non-syndromic traits of the causative gene. Conditions already included as part of other classifications or groups of diseases (vesiculobullous disorders, palmoplantar keratodermas, etc.) are not included in the ED classification. Complex syndromes that have ED signs, but also major non-ED signs, such as trisomy 21, are also excluded from the ED classification scheme.

The genetic causes of greater than 50% of the ED’s have been determined. The classification scheme clusters the disorders based on genotype, molecular pathway and physical characteristics (phenotype). Categories are:

  • EDA/NF KappaB Pathway
  • WNT Pathway
  • TP63 Pathway
  • Structure Group (Proteins important for the structure or function of the cell)
  • Other/Unknown

 Conditions that meet the definition of ED but of unknown cause are grouped with other EDs that share the most similar phenotype. Once their genetic cause is identified, they can be classified with the appropriate category or become the anchor of a new cluster, depending on molecular etiology.

What are the treatments for ectodermal dysplasias?

Treatment depends upon the specific disease manifestations in the affected individual, and is largely aimed at minimizing symptoms. For most of the ED’s, multidisciplinary management is required, with involvement of primary care physicians, geneticists, dermatologists, multiple dental specialists, nutritionists, speech therapists, otolaryngologists, ophthalmologists, orthopedic surgeons and/or plastic surgeons.

What are the risk factors for ectodermal dysplasias?

ED’s have been reported from essentially all races, ethnic groups and geographic regions.

Is there a cure/medications for ectodermal dysplasias?

Ectodermal dysplasias is, regrettably, incurable. Instead, the objective is to effectively control the symptoms so that the person can live a healthy life with a high quality of life.

  • Each person will receive a different treatment regimen because each kind of ectodermal dysplasia has a different set of symptoms. While some people just have minor symptoms that may be treated, others may have serious health problems that require complicated care.
  • Encourage the use of air conditioning at home, school, and work for patients who have anhidrosis or hypohidrosis. To maintain proper hydration and thermoregulation, encourage regular ingestion of cool liquids. Finally, tell patients to dress coolly.
  • Encourage routine dental hygiene and early dental evaluation and intervention for patients who have dental defects.
  • For the diagnosis, assessment, and treatment of patients with ectodermal dysplasia, including the use of dental implants, recommendations from an international consensus meeting of specialists in pediatric dentistry, orthodontics, and prosthodontics have been published.
  • Wigs can be worn by alopecia patients to enhance their appearance. In a small number of patients, topical minoxidil use, either with or without topical tretinoin, has been proven to promote hair growth.

Poorly developed fingernails,Inability to sweat
Problems with the tear ducts,Poorly developed teeth

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