5.When genes go wrong

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Genes in our cells are like small screws and bolts of a car. Even if a single bolt falls the car might behave differently. Various chemicals, rays, radiations,intrinsic and extrinsic factors of the environment may distort the function and structure of a DNA a strand called genes. These leads to hundreds of abnormalities. This session of DR S Biswas describes few of them.

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Presentation Transcript

Slide 1 :

Uncontrolled diabetes : Uncontrolled diabetes

Slide 3 : Homozygous autosomal recessive disorder Absence of enzyme phenyl alanine hydroxylase Thus amino acid, phenylalanine cannot be converted by tyrosine. Phenylalanine accumulates in the blood Undergoes transamination to form phenyl pyruvic acid and its products as phenyl lactic acid and phenyl acetic acid are produced. AMINO ACID METABOLISM Phenylketonuria

Slide 4 : Products are excreted in urine Gives "mousy" adour" to urine. Child is mentally retarded seizures, Psychoses and eczema.

Slide 5 : "Screening test" for the presence of phenyl pyruvate from urine is done with Ferric chloride which makes urine, green. These children can be treated by giving diet having very low levels of phenyalanine. Tyrosine constitues as an essential amino acid and must be provided in the diet.

Slide 6 : A rare in born error Hereditary defect in metabolism of phenylalanine and Tyrosine. It is first metabolic disorders discovered by Garrod. It is also due to autosomal recessive gene Incidence…. 2 to 5 per million live births. Due to lack of the enzyme homogentisate oxidase. Alkaptonuria

Slide 7 : Homogentisic acid accumulates in the tissues and blood and appears in urine. Most striking feature … dark urine. Deposition of homogentisic acid in cartilages of ears and other exposed places Generalised pigmentation of connective tissues Deposition in joints leading to arthritis, a condition called Ochronosis.

Slide 8 : Characterized by "hypomelanosis", Arising from inherited defects in the pigment cells (melano cytes) of eye and skin. Both of albinoas have melanocytes which are unable to synthesize tyrosinase. Melanin is thus absent in hair, eyes and skin. Albinism

Albino boy and an albino chimp : Albino boy and an albino chimp

Albinism : Albinism

Hit at … http://bisbio.in orCall 09814016083, 09855516083 oremail … bisbioin@gmail.com or amanbiswas60@gmail.com : Hit at … http://bisbio.in orCall 09814016083, 09855516083 oremail … bisbioin@gmail.com or amanbiswas60@gmail.com For all your Biology Problems UGC/ CSIR NET Life Sciences PMT SAT Advance Program Civil Services Entrance to Biotechnology and Post graduate Sciences

Slide 12 : This presentation is brought to you by Bisbio.in in collaboration with wiziq.com Many a thanks to Dr Aman Biswas The pictures projected on this free session belong to the beholder s on the internet. We thank all of them