Porphyria. The disease of the vampires?
welcome to the new post in the science series.
Today we will be discussing about the disease called as prophyria and we will know why this is called a vampire disease.
These are the group of genetic disorders of heme synthesis. Heme is a component of our haemoglobin, (Hb)Haemoglobin is made up of Heme and globin. Heme is nonproteinous part whereas globin is a chains of proteins(alpha and beta). Hb carries the oxygen within the red blood cells and helps in adequate oxygen supply to the tissues. Anemia is a condition where Hb is decreased and patient develops symptoms of decreased blood oxygen and its consequences.
Fig- Haemoglobin, central heme molecule surrounded by globin chains
Heme is synthesized from amino acid along with iron molecules, it requires 8 steps of chemical reactions to produce a heme and various enzymes are required for it.
When there is abnormality in the gene that produce enzymes for the heme synthesis there is accumulation of precursor substances and they are toxic for our body.
Porphyrias are basically due to accumulation chemical substances called prophyrins in the different body tissues
Fig- Heme synthesis and different types of prophyrias
What is the cause of porhyria?
Almost all of the porphyrias are genetic in origin. Some are autosomal dominant and some are autosomal recessive .Merely having the genetics does not mean you will develop symptoms, some triggering factors are involved in the disease process.Various drugs like sulphonamides, rifampicin, barbiturates, metronidazole , ketamine, progesterone, anticonvulsants and sunlight exposure, smoking trigger this disease.
Types of prophyrias
Broadly prophyrias are divided into acute and chronic type-
Acute- It consists of ALAD , Acute Intermittent porphyria, variegated porphyria and hereditary porphyria. it mostly involves the brain and the common symptoms are Nausea vomiting, headache, pain abdomen, increased heart beat and increased blood pressure.
In severe case patient may develop paralysis , confusion , hallucinations and other neurological symptoms.
Chronic - It consists of Porphyria cutanea tarda, Congenital erythropoietic porphyria and erythropoitic porphyria.
In most of these chronic porphyrias the porphyrins are deposited in the skin and other superficial tissues, they mainly manifest as skin disease and rarely as neurological symptoms.
Why porphyrias are called as diseases of vampires?
Due to the deposition of porphyrins in different body tissues person develops many signs which are similar to the vampire stories we see in the movies.
- Skin - The patients of porphyrias can not stand the sunlight. the porphyrins deposited in the cutaneous tissues gets excited in exposure to the sunlight and energy is released from the electrons, this results in fragile skin, intense pain ,itching and blistering of skin that gives a frightening look to the person. Thats why they prefer to live in the dark. They only come out of the house when sun goes down.
Fig.- patient of cutaneous porphyria,shows blistering of skin, loss of scalp hair & sharp deformed teeth
Teeth - The deposits in teeth cause delayed growth, abnormal brown pigmentation of teeth and hypertrophy of gum.Teeth are often sharp nail like.
Nose, lips and mouth -there is progressive inflammation and scaring of these tissues , eventually there is shortening of nose, deformity of nose and lips.
Neurological Behaviour - These people often suffer from depression anxiety mania , that causes them to do the antisocial activities.
King George III had developed acute mania, but it was diagnosed after 30 yrs of his death that he had suffered from porphyria. later in 2005 arsenic and antimony was found to be the cause of this.
- Nail and hair - hair growth is impaired in normal sites and there may be abnormal hair growth in the forehead, there is deformity of the nails.
These all symptoms and sign give some frightenig look to the patient.
Is this disease curable??
Treatment is based on the type of porphyria where it is neurological form or the cutaneous form. drugs are given for relieving the symptoms. Along with the drugs avoidance of the precipitating factors will be helpful in minimizing the symptoms.
- Intravenous Heme is given which inhibits the production of porphyrins,.Regular blood purification for reducing the excess iron which is toxic for the body.
- Avoiding the precipitating factors like Sunlight exposure ,smoking and fasting(calorie deprivition). Using protective clothings to prevent exposure from sunlight.
- Drugs like sulphonamides, rifampicin, barbiturates, metronidazole , ketamine, progesterone, anticonvulsants trigger this disease in individual with genetic predisposition, care must be taken during intake of these
- Prompt treatment of infections.
- Vitamin D supplement for compensation of decreased sunlight exposure.
- Follow @himal for more of these posts.