9/7/2015Mahia Samaha Alkony1 Genetics By: Mrs. Mahdiah Samaha Alkony

9/7/2015Mahia Samaha Alkony2 introduction   There is an ongoing need to identify women with increased risk of having a child with a serious genetic disorder so that they can be offered genetic counseling and appropriate genetic testing.   Nurses are needed to actively identify and refer high-risk patients and their families to appropriate professionals and to meet the special psychosocial needs of those women who must deal with genetic disorders and congenital anomalies.   Nurses, as primary providers of health services, are in a unique position to meet these challenges.

9/7/2015Mahia Samaha Alkony3 Definition   Genetics: is the science of heredity   Genes: are the coded sequence of information to which cellular organisms regulating their embryologic development, metabolic functioning, growth, and reproductive.   Approximately 1 in 50 newborns(2%) has a major congenital abnormality   60% of these abnormalities are caused by environmental factors and nutritional deficiencies.   40% are thought to be hereditary   60% of the first trimester spontaneous abortion the conceptus has chromosomal abnormalities.

9/7/2015Mahia Samaha Alkony4 BURDEN OF GENIRITIC Diseases to family of community   Financial cost to family   Decrease in planned family size   Loss of family integrity   Social Isolation   Lifestyle alteration

9/7/2015Mahia Samaha Alkony5 BURDEN OF GENIRITIC Diseases to family of community   Disruption of husband-wife relationship   Threatened family self concept   Psychological damage   Physical health problems   Loss of dreams at aspiration

9/7/2015Mahia Samaha Alkony6 Etiology of genetic disorders Chromosome disorders demonstrate change in the number or structure of an individual’s chromosome complement.

9/7/2015Mahia Samaha Alkony7 Types of chromosomes abnormalities   Monosomy: is the absence of a single chromosome and is almost always lethal to the embryo.   Trisomy: is the presence of an extra chromosome and is also usually incompatible with life.

9/7/2015Mahia Samaha Alkony8 Causes of chromosomal abnormalities   Radiation   Drugs   Viruses   Toxins   Chemicals   Women whose age is 35 years or more are at risk to get Down syndrome. This group of women must be referred to genetic counseling.

9/7/2015Mahia Samaha Alkony9 (2) Single gene inheritance   Refer to those genetic diseases that are caused by a gene mutation at a single site on a chromosome Autosomal dominant 2. 2.Autosomal recessive 3. 3.X-linked dominant 4. 4.X-linked recessive

9/7/2015Mahia Samaha Alkony10 (3) Multifactorial Inheritance   Those traits and disorders that arise as a result of the interaction of genetic and environmental factors.

9/7/2015Mahia Samaha Alkony11 Newborn genetic screening  Aim is to: Identify those pre symptomatic newborns affected with a genetic metabolic disease so that preventive treatment can be initiated before permanent damage is done. Screening done by obtaining sample from: 1. 1.cord blood 2. 2.Newborn nursery blood 3. 3.Newborn follow-up blood 4. 4.Newborn follow-up urine

9/7/2015Mahia Samaha Alkony12 Microbiologic assays screen done for:  Phenylketonuria( PKU)  Galactosemia  Screening for congenital hypothyroidism  screening for hemoglobinopathies  screening for cystic fibrosis

9/7/2015Mahia Samaha Alkony13 Maternal serum screening  Alpha-fetoprotein  Sickle cell disease  Beta thalassemia

9/7/2015Mahia Samaha Alkony14 Prenatal diagnosis   Amniocentesis   Fetoscopy   Chorionic villi sampling   Ultrasonography   Chromosome analysis

9/7/2015Mahia Samaha Alkony15 Genetic counseling Who should be offered prenatal diagnosis?  Maternal age 35years or more  Previous history of chromosomal abnormalities  Family history of metabolic or structural autosomal recessive or dominant disorder.  Couples who have a previous personal or family history of first or second-degree relative of a neural tube defect.  Clients who exhibit extreme anxiety or concern

9/7/2015Mahia Samaha Alkony16 Components of genetic counseling:  Initial interview  Family history  Assessment of client  Establishment of accurate diagnosis  Supplementary tests procedures  Literature search and review  Consultation with other experts  Determination of recurrence risk

9/7/2015Mahia Samaha Alkony17 Components of genetic counseling:  Communication of the results and risks to client and family  Discussion of option  Review of questions  Referral, e.g. amniocentesis  Follow-up  Evaluation