A 4- year-old child has been brought to OPD with a complaint of difficulty in walking. Physical examination reveals bowed legs, as shown in the picture . Make a probable diagnosis for this patient. What is the biochemical basis for this manifestation? What other manifestations could be present in this child? How will you confirm the diagnosis?
Answer- The child has bowed legs and appears to be suffering from Rickets. Rickets is caused by a failure of osteoid to calcify in growing children. It occurs due to vitamin D deficiency. Failure of osteoid to calcify in adults is called osteomalacia.
The other manifestations in rickets could be – frontal bossing, knock-knees, rachitic rosary along the costochondral junctions, Harrison groove and in more severe instances in children older than 2 years, vertebral softening leading to Kyphoscoliosis. In the long bones, laying down of uncalcified osteoid at the metaphysis leads to spreading of those areas, producing knobby deformity, which is visualized on radiography as cupping and flaring of the metaphysis.
The diagnosis is confirmed by estimating serum calcium, phosphorus, alkaline phosphatase and vitamin D levels. All are low except alkaline phosphatase which is high. Urinary calcium is decreased while phosphorus is increased.
A 32- year- old obese male has reported to the emergency with epistaxis. History reveals that he was on “Orlistat”for weight reduction since one year. What is the relationship between Orlistat and epistaxis?
Answer- The patient has most probably developed vitamin K deficiency. Absorption of vitamin K might have been decreased by Orlistat (weight loss medication). Vitamin K deficiency is uncommon in healthy adults but occurs in individuals with gastrointestinal disorders, fat malabsorption or liver disease, or after prolonged antibiotic therapy coupled with compromised dietary intake. Impaired blood clotting is the clinical symptom of vitamin K deficiency, which is demonstrated by measuring clotting time. In severe cases, bleeding occurs.
A child from a very poor socio economic background has reported with loss of vision. Ophthalmological examination reveals dry conjunctiva as shown in the picture. Make a probable diagnosis. What is the underlying cause for blindness?
Answer- The child is suffering from xerophthalmia (dryness of the conjunctiva) due to vitamin A deficiency. The earliest symptom of vitamin A deficiency is impaired dark adaptation, or night blindness. Severe deficiency causes xerophthalmia, ultimately resulting in corneal ulcers, scarring and blindness.
A 4 -year-old boy has been brought for consultation for bleeding gums and hematuria. He is the 12th born in a poor family, where one previous child died from malnutrition and dehydration in the period of infancy. The child is fed only with cow’s milk and biscuits. What could be the basis for these clinical manifestations?
Answer- The child is suffering from Scurvy (Vitamin C deficiency). The incidence of scurvy peaks in children who are fed a diet deficient in citrus fruits or vegetables. Vitamin C is necessary for the triple-helix formation of collagen. Deficiency of vitamin C leads to impaired collagen synthesis, causing capillary fragility, poor wound healing, and bony abnormalities in affected adults and children. Bleeding from gums and from other sites after a minor trauma, are typical of vitamin C deficiency. Edema may occur late in the disease.
A term infant is born and does well with breast-feeding. Two days later, the mother calls frantically because baby is bleeding from the umbilical cord and nostrils. What is the cause of bleeding? How can this be treated?
Answer- The child is suffering from vitamin K deficiency.
Hemorrhagic disease of newborn is caused by poor transfer of maternal vitamin K through placenta and by lack of intestinal bacteria in the infant for synthesis of vitamin K. The intestine is sterile at birth and becomes colonized over the first few weeks.
Vitamin K is required for the synthesis of blood clotting proteins. Vitamin K is the coenzyme for the carboxylation of the glutamate residues in the post translational modifications of proteins to form the unusual amino acid γ-carboxy Glutamic acid. γ-Carboxyglutamate chelates calcium ions, and so permits the binding of the blood clotting proteins to membranes.
Because of these factors, Vitamin K is routinely administered to newborns. Deficiency of fat soluble vitamins A, E, D and K can occur with intestinal malabsorption, but avid fetal uptake during pregnancy usually prevents infantile symptoms.
A 20 –year-old female has reported with glossitis and angular stomatitis. She is a strict vegetarian and belongs to a hilly region where cereals are traditionally dried in the open air and are thus exposed to sunlight. She frequently gets this problem. What be the cause for her problem?
Answer- The patient has riboflavin deficiency.
Riboflavin is found mainly in food of high nutritional value such as meat, milk, eggs and germs of cereals. Therefore, riboflavin deficiency is always associated with malnutrition or hypo-alimentation. Riboflavin is photosensitive and disintegrates when food is dried or stored in open daylight.
Riboflavin deficiency mostly manifests itself at the edge of the mucosa. Frequently, there are painful fissures at the angles of the mouth (angular stomatitis), fissures of the lips (Cheilosis), an inflammation of the periglottis (glossitis) and a seborrheic dermatitis of the nasolabial area and the eyelids .
Which vitamin supplementation is given to a pregnant mother to protect the fetus from neural tube defects?
Answer-Neural Tube Defects (NTDs) are birth defects of the brain and the spinal cord. In anencephaly, upper end of the neural tube fails to close. The brain either never completely develops or is totally absent. In spina bifida, neural tube fails to close on lower end. Spinal cord and back do not develop properly. Encephalocele causes protrusion of brain or membranes through an occipital defect of the Neural Tube.
It has been demonstrated that periconceptional (before and during the first 28 days after conception) supplementation of women with folic acid can decrease the risk of neural tube defects (malformations of the brain and spinal cord, causing anencephaly or spina bifida). Therefore, a daily intake of 400 µg folic acid in addition to a healthy diet 8 weeks prior to and during the first 12 weeks after conception is recommended. There is evidence that adequate folate status may also prevent the incidence of other birth defects, including cleft lip and palate, certain heart defects and limb malformations. To reduce the risk of neural tube defects, cereal grains are fortified with folate in some countries.
What is egg white injury ?
Raw egg whites contain Avidin, a glycoprotein that strongly binds with biotin and prevents its absorption. Thus, the ingestion of large quantities of raw egg white over a long period can result in a biotin deficiency.Cooking denatures avidin which prevents its binding with biotin, hence no deficiency upon consumption of cooked eggs.
Maize eaters generally have skin rashes resembling pellagra. What is its biochemical basis?
Answer- Maize lacks Tryptophan, and niacin present in it is bound to certain components and is not bioavailable. Tryptophan contributes as much as two-thirds of the niacin activity required by adults in typical diets. Lack of tryptophan and niacin in maize causes niacin deficiency manifested as pellagra. Specific food processing, such as the treatment of corn with lime water, increases the bioavailability of nicotinic acid in these products and can prevent pellagra. Pellagra is characterized by a photosensitive dermatitis. As the condition progresses, there is dementia and possibly diarrhea. Untreated pellagra is fatal.
The blood picture of a strict vegetarian female patient, presenting with weakness, fissured tongue and paralysis is displayed. Make a probable diagnosis. What will be the line of treatment?
Answer- The patient is suffering from megaloblastic anemia. Although it is synthesized exclusively by microorganisms, for practical purposes vitamin B12 is found only in foods of animal origin, there being no plant sources of this vitamin. This means that strict vegetarians (Vegans) are at risk of developing B12 deficiency. Vitamin B12 Deficiency Causes Functional Folate Deficiency—the “Folate Trap”. Deficiency of folic acid itself or deficiency of vitamin B12, which leads to functional folic acid deficiency, affects cells that are dividing rapidly because they have a large requirement for thymidine for DNA synthesis. Clinically, this affects the bone marrow, leading to megaloblastic anemia. A combination of folic acid and B12 is given to treat megaloblastic anemia.
Why is it said that babies undergoing phototherapy for physiological jaundice are prone to develop riboflavin deficiency?
Answer- Riboflavin is stable when heated and is not easily destroyed in the ordinary processes of cooking but it is light-sensitive so it is degraded easily by light, that is why infants undergoing phototherapy for jaundice become prone to this deficiency. Loss of riboflavin is also seen if foods are left out in sunlight or in UV light. Because of this light sensitivity, riboflavin rapidly disappears from milk kept in glass bottles exposed to the sun or bright daylight (85% within 2 hours).
A 56 – year-old male on Isoniazid Therapy for tuberculosis has developed rashes on the exposed parts of the body. What is the probable cause for these rashes?
Answer- The patient has developed pellagra. Prolonged treatment with the anti-tuberculosis drug, Isoniazid, has resulted in niacin deficiency. Isoniazid may induce a state of pyridoxine deficiency by combining with pyridoxine and generating inactive isoniazid-pyridoxal hydrozones, thus depleting the supply of pyridoxine. Pyridoxine is needed in the endogenous pathway of niacin synthesis. Thus diminished synthesis of niacin ultimately produces pellagra, which is manifested by skin rashes as seen in the picture.Please help "Biochemistry for Medics" by CLICKING ON THE ADVERTISEMENTS above!