Genetic Disorders:

Mendelian (Monogenic) DiseasesPrepared by:

Shaina Mavreen D. Villaroza

Mendelian Diseases

Definition: Diseases in which the phenotypes are largely determined by the action, lack of action, of mutations at individual loci.Rare 1 % of all live born individuals4 types of inheritance Autosomal dominant Autosomal recessive X linked dominant X linked recessive Example: Hemophilia

Chromosome theory. http://chsweb.lr.k12.nj.us/mstanley/outlines/chromotheory/chromotheory.html

Autosomal DominantOffspring has a 50:50 chance of being affectedBoth sexes equally affectedExamples ABO Blood Group System Retinoblastoma Neurofibromatosis Marfans syndrome Familial polyposis coli

Marfansyndrome. http://intranet.tdmu.edu.ua/data/kafedra/internal/i_nurse/classes_stud/RN-BSN%20Program/Full%20time%20study/First%20year/professional%20nursing%20role%20transition%20practicum/09.%20Practice%20nursing%20care%20to%20clients%20with%20CTD%20II.htm

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Autosomal RecessiveProbability 25% (1:4)Both sexes equally affectedExamples Hemoglobinopathies: sickle cell anaemia, thalassemia Inborn errors of metabolism:PKU,Alkaptonuria Albinism Cystic Fibrosis Hirschsprung disease

Google Images What causes congenital adrenal hyperplasia (CAH)?https://www.nichd.nih.gov/health/topics/cah/conditioninfo/Pages/causes.aspx

X linked dominantAffected FatherDaughters are affected, sons escape

ExamplesVitamin D resistant RicketsFamilial hypophosphatemiaBlood group Xg

Vitamin D Metabolism and Rickets. https://xlhnetwork.org/xlh.pl?f=larry/website/VitaminD/vitaminD.html

X-Linked RecessiveCarrier MotherA mutant gene on X chromosome in males will express itself readily as there is no normal allele, but a mutant gene on X chromosome of females will not express itself in the presence of a normal alleleExamples Hemophilia Colour blindness Duchenne muscular dystrophy G6PD deficiency

HemophiliaX-Linked RecessiveGENERAL DESCRIPTION and EPIDEMIOLOGYIs a heredity blood disease by delayed blood clotting or the blood doesnt clot normallyAbsence of factor in blood antihemophilic globulinSex-linked disorder, genes are located on the X chromosome

Blood Disordershttp://www.rchsd.org/health-articles/hemophilia/Causes, Symptoms And Treatment Of Hemophilia. http://mytips10.blogspot.com/2015/07/causes-symptoms-and-treatment-of-hemophilia.htmlEgyptian Hemophilia Needs Your Attention. http://sadtimedays.blogspot.com/2012/08/egyptian-hemophilia-needs-your-attention.htmlHemophilia. https://suncfb1.wikispaces.com/Hemophilia

HemophiliaSigns and SymptomsSpontaneous bleedingProlonged bleeding from cutsNosebleeds with no known causeTightness in your jointsInternal bleedingBruising, especially a large, lumpy bruise.Blood in the urine or stool

Hemophilia Causes, Symptoms, Diagnosis And Treatmenthttp://www.doctortipster.com/6480-hemophilia-causes-symptoms-diagnosis-and-treatment.html Stock Photography:Joint Bleeds In Hemophilia. http://www.dreamstime.com/stock-photography-joint-bleeds-hemophilia-image27394012

What is Involved in Making a Diagnosis of Hemophilia?http://www.wisegeek.com/what-is-involved-in-making-a-diagnosis-of-hemophilia.htm

HemophiliaPathogenesisHemophilia occurs when you have a deficiency in one of these clotting factors (platelets and plasma proteins).Hemophilia is inherited.However, in some cases, hemophilia is caused by a genetic change (spontaneous mutation).

Hemophilia A,the most common type, is caused by insufficient clotting factor VIII.Hemophilia B,the second most common type, is caused by insufficient clotting factor IX.Hemophilia C,in which signs and symptoms are often mild, is caused by insufficient clotting factor XI.

(C) Hemophilia patient dies in drug-deficient hospital. http://www.greaterkashmir.com/news/health/-hemophilia-patient-dies-in-drug-deficient-hospital/208387.html

HemophiliaCurrent TreatmentNo cure, yet.But can be treated:Treatment for bleeding episodesMild hemophilia A.Slow injection of the hormone desmopressin (DDAVP) into a vein can stimulate a release of more clotting factor to stop bleeding. Occasionally, DDAVP is given as a nasal medication.Moderate to severe hemophilia A or hemophilia B. Bleeding may stop only after an infusion of recombinant clotting factor or clotting factor derived from donated human blood. Repeated infusions may be needed if internal bleeding is severe.Hemophilia C.Clotting factor XI, the factor missing in this type of hemophilia, is available only in Europe. In the United States, plasma infusions are needed to stop bleeding episodes.

Ongoing treatmentRegular infusions of DDAVP or clotting factorClot-preserving medications (antifibrinolytics)Fibrin sealantsPhysical therapyFirst aid for minor cutsVaccinations

References:Diseases and Conditions Hemophilia. Published on September 26, 2014. Retrieved on May 1, 2016 from http://www.mayoclinic.org/diseases-conditions/hemophilia/basics/definition/con-20029824Hemophilia Treatments and drugs. Retrieved on May 1, 2016 from http://www.mayoclinic.org/diseases-conditions/hemophilia/basics/treatment/con-20029824Symptoms of Hemophilia. Retrieved on May 1, 2016 from http://www.seattlechildrens.org/medical-conditions/chromosomal-genetic-conditions/hemophilia-symptoms/

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