9/7/2015mahia samaha alkony1 genetics by: mrs. mahdiah samaha alkony

04/19/2304/19/23 Mahia Samaha AlkonyMahia Samaha Alkony 11

GeneticsGenetics

By: Mrs. Mahdiah Samaha AlkonyBy: Mrs. Mahdiah Samaha Alkony


introductionintroduction

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.


DefinitionDefinition

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.


BURDEN OF GENIRITICBURDEN OF GENIRITICDiseases to family of communityDiseases to family of community

Financial cost to family

Decrease in planned family size

Loss of family integrity

Social Isolation

Lifestyle alteration


BURDEN OF GENIRITICBURDEN OF GENIRITICDiseases to family of Diseases to family of

communitycommunity Disruption of husband-wife relationship

Threatened family self concept

Psychological damage

Physical health problems

Loss of dreams at aspiration


Etiology of genetic Etiology of genetic disordersdisorders

Chromosome disorders demonstrate change in the number or structure of an individual’s chromosome complement.


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.


Causes of chromosomal Causes of chromosomal abnormalitiesabnormalities

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.


((22 ) )Single gene inheritanceSingle gene inheritance

Refer to those genetic diseases that are caused by a gene mutation at a single site on a chromosome.

1. Autosomal dominant

2. Autosomal recessive

3. X-linked dominant

4. X-linked recessive


((33 ) )Multifactorial InheritanceMultifactorial Inheritance

Those traits and disorders that arise as a result of the interaction of genetic and environmental factors.


Newborn genetic screening

Aim is to: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. cord blood2. Newborn nursery blood3. Newborn follow-up blood4. Newborn follow-up urine


Microbiologic assays screen done for:

Phenylketonuria( PKU)Phenylketonuria( PKU) GalactosemiaGalactosemia Screening for congenital hypothyroidismScreening for congenital hypothyroidism screening for hemoglobinopathies screening for hemoglobinopathies screening for cystic fibrosis screening for cystic fibrosis


Maternal serum Maternal serum screeningscreening Alpha-fetoproteinAlpha-fetoprotein Sickle cell diseaseSickle cell disease Beta thalassemiaBeta thalassemia


Prenatal diagnosisPrenatal diagnosis

Amniocentesis Fetoscopy Chorionic villi sampling Ultrasonography Chromosome analysis


Genetic counselingGenetic counseling

Who should be offered prenatal diagnosis?Who should be offered prenatal diagnosis? Maternal age 35years or moreMaternal age 35years or more Previous history of chromosomal abnormalities Previous history of chromosomal abnormalities Family history of metabolic or structural autosomal Family history of metabolic or structural autosomal

recessive or dominant disorder.recessive or dominant disorder. Couples who have a previous personal or family Couples who have a previous personal or family

history of first or second-degree relative of a neural history of first or second-degree relative of a neural tube defect.tube defect.

Clients who exhibit extreme anxiety or concern Clients who exhibit extreme anxiety or concern


Components of genetic counselingComponents of genetic counseling::

Initial interviewInitial interview Family historyFamily history Assessment of clientAssessment of client Establishment of accurate diagnosisEstablishment of accurate diagnosis Supplementary tests proceduresSupplementary tests procedures Literature search and reviewLiterature search and review Consultation with other expertsConsultation with other experts Determination of recurrence risk Determination of recurrence risk


Components of genetic counselingComponents of genetic counseling::

Communication of the results and risks to Communication of the results and risks to client and familyclient and family

Discussion of optionDiscussion of option Review of questionsReview of questions Referral, e.g. amniocentesisReferral, e.g. amniocentesis Follow-upFollow-up Evaluation Evaluation

9/7/2015mahia samaha alkony1 genetics by: mrs. mahdiah samaha alkony

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