Transcript Birth Defect

Unit 2: Infant Mortality:
Leading Causes
2006: Infant mortality rate: 6.69/1000 births
2011: Infant mortality 6.05/1000 births
The good news: Infant
mortality rates are
improving
Recent Trend in Infant Mortality,
United States
Recent Trend in Infant Mortality,
United States
Source: State Center for Health Sta
In 2005, the US ranked 30th in infant
mortality.
DISPARITY: (dis-par-i-ty) literally
means inequality.
In health, for example, it can refer to an
inequality of access to and quality of
health care among people of different
races or ethnicities or people living in
different geographical areas.
There are two major DISPARITIES
recognized in Infant Mortality
Geographical
Race/Ethnicity
The two often co-occur
Look at the maps and charts that follow to better
understand disparities in infant mortality.
Recent Trend in Infant Mortality,
United States 2011
Recent Trend in Infant Mortality, U.S.
Percent Change 2005 - 2010
Infant Mortality Rates by race and ethnicity
Infant Mortality Rates by race and ethnicity
% change 2005 - 2011
Top 5 causes of infant mortality
Low Birth Weight Defined
Low Birth Weight - infants completing 37
weeks gestation and weighing less than 2500
grams at birth.
Very Low Birth Weight - infants completing
37 weeks gestation and weighing less than
1500 grams at birth.
Low Birth Weight, U. S
less than 2500 grams (5 1/2 pounds)
.
Low Birth Weight, U. S
less than 2500 grams (5 1/2 pounds)
.
Preterm Birth Rates as a Function of Maternal Age
Preterm Birth Rates as a Function of Race of Mother
Birth Defect
An abnormality of structure, function or body
chemistry, whether genetically determined or
the result of environmental interference.
It may to present at birth or appear later in
life.
Overview of birth defects
1 in 33 babies are born with birth defects
Malformations or genetic abnormalities cause
7-20% of stillbirths
Chromosomal abnormalities cause up to 70%
of first-trimester miscarriages and 20% of
second-trimester miscarriages
30% of all pediatric admissions
10,500 deaths per year
Major factors responsible for
birth defects
Abnormalities of individual genes - truly inherited,
includes blood disorders and in-born errors of
metabolism
Chromosomal abnormalities - either number or
alignment
Intrauterine injury - caused by a teratogenic agent,
naturally occurring or environmentally induced
Multifactorial circumstances - environmental factors
acting on a genetically predisposed embryo
What are chromosomes?

Chromosomes are tiny string-like structures in
cells of the body. Composed of coiled DNA that
contains the estimated 20,000 to 25,000 human
gene pairs that determine traits like eye and hair
color, as well as direct the growth and
development of every part of our physical and
biochemical systems.
Each person normally has 23 pairs of
chromosomes, or 46 in all. We normally inherit
one chromosome per pair from our mother and
one from our father.
Where are Genes?
What are genes?
•A sequence of nitrogen bases within the
DNA strands.
•Basic unit of inheritance.
•Determines both the structure and
function of the organism.
GENES
Allele: one member of a pair of genes (small pieces of
DNA) located at a specific spot on a chromosome.
We inherit two alleles for each gene: one from each parent
The expression of traits is associated with alleles
Protein Construction
Four nitrogen bases code for the construction
of all proteins in the cytoplasm of the cell.
In order for the codes to be made operational,
several steps occur:
1.Transcription of mRNA by DNA in cell nucleus
2.mRNA moves to cytoplasm to direct protein
synthesis
3.tRNA brings AA’s for placement in protein chain
(Translation)
Some genetic disorders caused by genetic mutations
Dominant:
One mutated copy of gene is all that is
needed to affect someone.
Recessive
Two mutated copies of gene needed
to affect someone
Co-dominate Two different versions of gene expressed as
in the AB blood type (this is not a disorder)
Sex-linked
X-linked: genes on X chromosome