Diseases Due to Defective Cell Organelles

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1. AMISHA 17BCB0022 DISEASES DUE TO DEFECTIVE CELL ORGANELLES 11-03-2018 1 Amisha 17BCB0022 Cell Biology And Biochemistry

2. INTRODUCTION TAY-SACHS DISEASE DIABETES MELLITUS AND DEAFNESS ADRENOLEUKODYSTROPHY ACHONDROGENESIS CONCLUSION 11-03-2018 2 Amisha 17BCB0022 CONTENTS

3. An organelle is a membrane bound structure found within a cell. These mini-organs are bound in a double layer of phospholipids to insulate their little compartments within the larger cells. The cell organelles are found in the cytoplasm, which is a viscous liquid found within the cell membrane that houses the organelles and is the location of most of the action happening in a cell. A disease is a particular abnormal condition that affects part or all of an organism  caused by external force and that consists of a disorder of a structure or function, usually serving as an evolutionary disadvantage. It is often used more broadly to refer to any condition that causes pain, dysfunction, distress, social problems, or death to the person afflicted, or similar problems for those in contact with the person. 11-03-2018 3 Amisha 17BCB0022 INTRODUCTION

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5. Lysosomes are cell organelles that break down the waste materials inside the cells. Tay -Sachs disease is related to the malfunction of the lysosomes . It is a rare, neurodegenerative disorder in which deficiency of an enzyme ( hexosaminidase A) results in excessive accumulation of certain fats lipids known as gangliosides in the brain and nerve cells. When too much fatty material builds up in the lysosome , it becomes toxic destroying the cell and damaging surrounding tissue. This abnormal accumulation of gangliosides leads to progressive dysfunction of the central nervous system. 11-03-2018 5 Amisha 17BCB0022 TAY-SACHS DISEASE

6. SIGNS AND SYMPTOMS   Tay-Sachs disease is broken down into the classic or infantile form, the juvenile form, and the adult or late-onset form. In individuals with infantile Tay-Sachs disease, symptoms typically first appear between three and five months of age. In individuals with the late-onset form, symptoms may become apparent anytime from adolescence through the mid-30s. Symptoms of Tay-Sachs in infants include: Deafness Progressive blindness Decreased muscle strength Increased startle response Paralysis or loss of muscle function Seizure Muscular stiffness (spasticity) Delayed mental and social development Slow growth Red spot on the macula (an oval-shaped area near the centre of the retina in the eye) 11-03-2018 6 Amisha 17BCB0022

7. DIAGNOSIS Tay-Sachs disease can be diagnosed before birth, through amniocentesis or chorionic villus sampling. In amniocentesis, a needle is inserted into the uterus through the abdomen and a sample of amniotic fluid is removed for testing. In chorionic villus sampling (CVS), a thin tube is inserted through the cervix and is used to extract a small sample of the placenta for testing. EXPECTED DURATION Tay-Sachs disease is a lifelong condition 11-03-2018 7 Amisha 17BCB0022

8. TREATMENT AND PREVENTION Since there's no cure for Tay-Sachs disease, the goal of treatment is support and comfort. Medication: To reduce your child's symptoms, a number of prescription medications are available, including seizure medications. Respiratory care:  Children who have Tay-Sachs disease are at high risk of lung infections that cause breathing problems and frequently accumulate mucus in their lungs. Respiratory therapists at Mayo Clinic have extensive experience in reducing the mucus using chest physiotherapy (CPT) and in training family members to provide CPT to your child at home. Physical therapy:  As the disease progresses, your child may benefit from physical therapy to help keep joints flexible and maintain as much ability to move (range of motion) as possible. Physical therapy can delay joint stiffness and reduce or delay the loss of function and pain that can result from shortened muscles. Family support:  Your child's clinic treatment team can provide resources and information to help you and your family cope with your child's needs. Your team can help connect you to local support groups. Follow-up care and coordination:  Your clinic doctor will provide treatment and follow-up care for your child and will coordinate the treatment and support plan with your child's primary care doctor or paediatrician 11-03-2018 8 Amisha 17BCB0022

9. Diabetes mellitus and deafness is a subtype of diabetes which is caused from a point mutation at position 3243 in human mitochondrial DNA, which consists of a circular genome. These genes are instruction for making specific tRNAs . They are used in adding amino acids in the right location of a protein. The mutations decrease the ability to add amino acids, including the ability to help signal insulin. This leads to diabetes. The impaired mitochondria affect the most active cells, for example, the cochlea (in the ear). Since mitochondrial DNA is contributed to the embryo by the  oocyte  and not by spermatozoa, this disease is inherited from maternal family members only.  It is characterized by diabetes and  sensorineural hearing loss. 11-03-2018 9 Amisha 17BCB0022 DIABETES MELLITUS AND DEAFNESS

10. SIGNS AND SYMPTOMS:   There are many different ways the disorder can affect the body. When they appear, and how severe the symptoms are depend from person to person Type 2 diabetes- dependence on insulin Symptoms include: Deafness: the most common symptom with diabetes Shorter height/ thinner Heart Problems Myopathy (Muscle Weakness) Kidney diseases Retina/Eye problems Gastrointestinal (Stomach/Intestine) Diseases 11-03-2018 10 Amisha 17BCB0022

11. TREATMENTS: Diabetes: First treated with dietary changes, or tablets. Within 2 years, insulin therapy Deafness : Rarely leads to total deafness. Hearing aids/ implants are helpful . periodic checkups on other functions ( i.e vision, kidneys, etc.) should be done. If a disorder is found, specific medication/therapy is used. 11-03-2018 11 Amisha 17BCB0022

12. Peroxisomes are cell organelles, that are very similar to lysosomes , have digestive enzymes which require oxygen to break down the toxic materials inside the cells. Adrenoleukodystrophy (ALD) is caused by malfunction of the peroxisomes . It is a disease which caused by the accumulation of very-long chain fatty acids in tissues throughout the body. The accumulation happened because the peroxisomes lacked the second most abundant protein in the outer membrane of this organelle. Normally, the missing protein transports an enzyme into the peroxisome . The enzyme controls breakdown of a type of very long chain fatty acid. Without the enzyme, the fatty acid builds up in cells in the brain and spinal cord, eventually stripping these cells of their fatty sheaths, made of a substance called myelin, that are vital for nerve transmission. The result of this is that the person will show abnormal withdrawal or aggression, poor memory, and poor school performance in children and progressive stiffness, weakness or paralysis of the lower limbs, and ataxia in adults. 11-03-2018 12 Amisha 17BCB0022 ADRENOLEUKODYSTROPHY (ALD)

13. SIGNS AND SYMPTOMS muscle spasms seizures trouble swallowing loss of hearing crossed eyes impaired vision hyperactivity paralysis coma deterioration of fine motor control trouble with language comprehension stiffness in the legs difficulty thinking and remembering visual perceptions 11-03-2018 13 Amisha 17BCB0022

14. TREATMENTS: Treatment methods depend on the type of ALD you have . Steroids can be used to treat Addison’s disease. There are no specific methods for treating the other types of ALD . switching to a diet that contains low levels of VLCFAs taking Lorenzo’s oil to help lower elevated VLCFA levels taking medications to relieve symptoms such as seizures doing physical therapy to loosen muscles and reduce spasms Doctors continue to look for new ALD treatments. Some doctors are experimenting with bone marrow transplants. If children with childhood cerebral ALD are diagnosed early, these experimental procedures may be able to help. 11-03-2018 14 Amisha 17BCB0022

15. The function of the Golgi apparatus is to modify, sort and package the macromolecules that are synthesized by the cells for secretion purposes or for use within the cell. They are also involved in the transport of lipid molecules around the cell and create lysosomes . Achondrogenesis type 1A is caused by a defect in the microtubules of the Golgi apparatus . Achondrogenesis is a rare and severe group of genetic disorders that results in a short trunk, small limbs, and a narrow chest. It occurs when a person’s body does not produce enough growth hormone. As a result, cartilage and bone do not develop properly, causing abnormalities in the skeletal system. 11-03-2018 15 Amisha 17BCB0022 ACHONDROGENESIS

16. SIGNS AND SYMPTOMS Type 1A Symptoms soft skull bone poorly formed spine and pelvic bones short and easily breakable ribs Type 1B Symptoms round belly pouch near the belly button short toes and fingers inwardly rotated feet Type 2 Symptoms short ribs poorly developed lungs cleft palate small chin large forehead and belly 11-03-2018 16 Amisha 17BCB0022

17. DIAGNOSIS Achondrogenesis is diagnosed by physical features, X-ray (radiographic) findings and examination of tissue samples under a microscope (histology). Molecular genetic tests for mutations in the   SLC26A2  gene can be used to confirm the diagnosis of achondrogenesis type 1B . Prenatal diagnosis of achondrogenesis by ultrasound is possible after 14-15 weeks gestation. Prenatal diagnosis by chorionic villus sampling (10-12 weeks gestation) or amniocentesis (15-18 weeks gestation) is possible if the specific gene mutations have been identified in a family member. TREATMENTS: Babies born with achondrogenesis usually die quickly because their small chests don’t allow them to breathe. Many die in utero . However, since its genetical , families that have this gene might have to rethink their decision to have a baby. 11-03-2018 17 Amisha 17BCB0022

18. Overall, we have learned that the failure by the cell organelle to function in a state of normalcy leads to a number of crippling diseases that might extend throughout a lifetime or in severe cases lead to death. With the advent of smarter technologies and devices, there has been a steady amelioration in the medical field. And by the end of the century there is and has always been a hope for a disease-free and untarnished mankind. 11-03-2018 18 Amisha 17BCB0022 CONCLUSION