The most common cause is high-carbohydrate feeds, leading to the overgrowth of thiaminase-producing bacteria, but dietary ingestion of thiaminase (e.g., in bracken fern), or inhibition of thiamine absorption by high sulfur intake are also possible. Another cause of PEM is Clostridium sporogenes or Bacillus aneurinolyticus infection. These bacteria produce thiaminases that can cause an acute thiamine deficiency in the affected animal. Snakes
Snakes that consume a diet largely composed of goldfish and feeder minnows are susceptible to developing thiamine deficiency. This is often a problem observed in captivity when keeping garter and ribbon snakes that are fed a goldfish-exclusive diet, as these fish contain thiaminase, an enzyme that breaks down thiamine. Wild birds and fish
Thiamine deficiency has been identified as the cause of a paralytic disease affecting wild birds in the Baltic Sea area dating back to 1982. In this condition, there is difficulty in keeping the wings folded along the side of the body when resting, loss of the ability to fly and voice, with eventual paralysis of the wings and legs and death. It affects primarily 0.5–1 kg-sized birds such as the European herring gull (Larus argentatus), common starling (Sturnus vulgaris), and common eider (Somateria mollissima). Researches noted, "Because the investigated species occupy a wide range of ecological niches and positions in the food web, we are open to the possibility that other animal classes may develop thiamine deficiency, as well."p.
Commonly used tests include a complete blood count (CBC), bone marrow examination, leukocyte telomere length test (e.g. Flow FISH), pulmonary function test, and genetic testing. Management
The mainstay of treatment in dyskeratosis congenita is hematopoietic stem cell transplantation, best outcome with sibling donor. Short term therapy in initial stages is with anabolic steroids [oxymetholone, danazol] or with erythropoietin-like hormones or with granulocyte-colony stimulating factor [filgrastim) all these therapies are directed to cope with effects of bone marrow failure which manifests as low red and white blood cell counts. These medications help to increase the blood components and make up for the deficiencies caused due to bone marrow failure. Dyskeratosis Congenita in regards to stem cell transplantation have to be very carefully treated with low intensity radiation/chemo to avoid potentially catastrophic effects of Host versus graft disease and toxicity to other organs affected by short telomeres which makes them very sensitive to any radiation especially the lungs, and liver. Prognosis
DC is associated with shorter life expectancy, but many live to at least age 60. Main cause of mortality in these patients are related to bone marrow failure. Nearly 80% of the patients of dyskeratosis congenita develop bone marrow failure. Research
Recent research has used induced pluripotent stem cells to study disease mechanisms in humans, and discovered that the reprogramming of somatic cells restores telomere elongation in dyskeratosis congenita (DKC) cells despite the genetic lesions that affect telomerase. The reprogrammed DKC cells were able to overcome a critical limitation in TERC levels and restored function (telomere maintenance and self-renewal).