1 / 19

Genetic Disease

Genetic Disease. By: Jean Liu ID: 08301016041. General Facts. Caused by an abnormality in an individual’s genome Can also be caused by environmental factors The abnormality can range from minuscule to major Point mutation (P) – insertion/deletion entirely inside one gene

sinead
Télécharger la présentation

Genetic Disease

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Genetic Disease By: Jean Liu ID: 08301016041

  2. General Facts • Caused by an abnormality in an individual’s genome • Can also be caused by environmental factors • The abnormality can range from minuscule to major • Point mutation (P) – insertion/deletion entirely inside one gene • Deletion (D) – removal of a gene or genes • C – whole chromosome extra, missing or both • Trinucleotide repeat disorder (T) – gene is extended in length

  3. Xeroderma PigmentosumWhat Is It ? • Very rare inherited skin disorder • A person is highly sensitive to the sunlight (photosensitive) • Autosomal recessive genetic disorder • DNA repair – ability of repair damage caused by ultraviolet (UV) light • Six times more common in Japanese people than in other groups • Around 1 in 40,000 • Equal numbers of male and female patients • Less than 40% of individuals with XP survive beyond age 20 years • Those with milder disease may survive beyond middle age * Malignancy – medical condition that can progress, potentially result in death; eg: tumors

  4. Xeroderma PigmentosumTypes

  5. Xeroderma PigmentosumHow is it inherited ? • Genetic Condition • Can be passed from generation to generation in • Autosomal recessive inheritance patter • Mutation must be present in both copies of the gene • Carrier – one copy of the gene mutation • When both parents are carrier, there is a 25% chance that the child will be affected

  6. Xeroderma PigmentosumSymptoms • Skin • Eyes • Neurological

  7. Xeroderma PigmentosumSkin Symptoms • Severe sunburn after a short sun exposure • May last for several weeks • Usually happens during a child’s first exposure to the sun • Development of freckles at an early age • Irregular dark spots • Thin skin • Excessive dryness of the skin • Premature aging of skin, lips, eyes, mouth and tongue • More than 1,000 times the risk of developing skin cancer

  8. Xeroderma PigmentosumEye Symptoms • Occur nearly 80% of the patients • Eyes are very sensitive to the sun (photophobia) • Irritated • Bloodshot • Cloudiness of the cornea • Darkening of the skin of the eyelids

  9. Xeroderma PigmentosumNeurological Symptoms • Only occur in 20-30% of people with XP • Tend to get worse over time • Hearing loss • Microcephaly • Spastic muscles • Stiffness or tightness of the muscles • Seizures • Intellectual impairment • Poor coordination

  10. Xeroderma PigmentosumClassifications • Mild • Light brown freckles on face • Moderate • Dark brown freckles on face • Burning on exposed parts of the body • Photophobia • Severe • Serious dark brown freckles • Burning on exposed/unexposed parts of the body • Cutaneous changes • Ocular changes

  11. Xeroderma PigmentosumCause

  12. Xeroderma PigmentosumComplications • Skin tumors • Most patients die of skin cancer early in adulthood • Eye tumors • Vitamin D deficiency • Some are hypersensitive to X-rays • Patients who smoke may develop lung cancer at a relatively young age

  13. Xeroderma PigmentosumDiagnosis • Tests • Blood samples • Urine samples • Skin biopsy • Eye exam • Clouding of the cornea – loss of transparency of the cornea • Keratitis – front part of the eye becomes inflamed • Lid tumors • Blepharitis – inflammation of the eyelash follicles • Fibroblast culture • DNA repair • UV sensitivity • Aminocentesis • Test before the birth of the child - take sample of fluid from the sac around the baby

  14. Xeroderma PigmentosumTreatment • There is no cure for XP so far • Many management methods to cope with the problems

  15. Xeroderma PigmentosumManagement • Physically • Reducing exposure to the sun • Sun glasses • Clothing (long sleeves, long pants, gloves) • Optical filtration • Lots and lots of sunscreens • Chemically • Reducing the number of keratoses with Isotretinoin • Housing • Halogen lamps * Keratoses – keratin (on the skin)

  16. Xeroderma PigmentosumManagement • Two parts • Headgear • Protect head and face • Suit • Covering the rest of the body • Filtering 100% UV-light

  17. Xeroderma PigmentosumPrevention • Focuses more on future problems • Frequent check-ups and examinations • Skin specialist (dermatologist) • Eye specialist (ophthalmologist)

  18. Xeroderma PigmentosumA Case In China • Wan Lao Yang – the girl who lives in the dark • An XP patient • Her facial tumors made it impossible for her to wear the UV protective suit • The cancer had spread to her lungs • Died on June 2006

  19. Genetic Disease By: Jean Liu ID: 08301016041

More Related