Comparitive Table of Birth Disorder Risks
In order of frequency*Glossary of inherited genetic disorders terms:
Disorders
with description of related problems:Cause: Mostly Affects: Risk: Screen/Treat Low Birth Weight, Stillbirth, SIDS
(Related problems for survivors include brain damage, breathing problems, anemia, heart conditions)Multi-factoral
Random
Background risk:
one out of every 15 birthsFirst Cousins: Consanguinity unlikely to cause an increase in risk
Most Common Causes:
- Maternal medical health and nutrition
- Smoking
- Drinking
Drug Use (Rx, OTC and illegal)Congenital Heart Defects * * Usually NOT genetic
Multi-factoral
common causes: environmental, viral, medicinal, alcholol and other substance use during pregnancyRandom
Background risk:
one out of every 150 birthsFirst Cousins: Consanguinity unlikely to cause an increase in risk
Screening:
Echo- CardiographyTreatment:
Pre- and Post-Natal treatments available
Cerebral Palsy
May have other problems such as mental retardation; learning disabilities; seizures; and vision, hearing and speech problemsMulti-factoral
Random
Background risk:
one out of every 350-500 birthsFirst Cousins:
Consanguinity unlikely to cause an increase in riskCommon Causes:
Infection during pregnancy, Premature birth, delivery trauma, Rh disease
Sickle Cell
Affects a protein inside the red blood cells called hemoglobin causing distorded cells. Pain, meningitis, stroke, and organ problems are associated with this disease.Recessive Genetic Gene must be present in BOTH parents for child to be affected:
African-American, also Hispanic, Caribbean and certain other ethnic groups
Background risk:
one out of every 400-600 birthsFirst cousins:
may increase risk up to 2x (2 out of every 400-600 births)Screening: Prenatal testing availale; Newborn testing is standard in 40 states. Treatment: infants should be treated with pennicillin to pevent fatality
Club Foot *
Mild to severe foot deformities
Multi-factoral
Usually a result of fetal positioning, although in rare incidents, can be dominant genetic.Rarely inherited!
Random
affects males 2x more often than females
Background Risk:
one out of every 735 birthsFirst Cousins:
Consanguinity unlikely to cause an increase in riskTreatment: Affects can be minimized by early treatment, i.e. casting, braces, or surgery FAS
(Fetal Alcohol Syndrome)
miscarriage, stillbirth, SIDS, low birthrate, mental retardation or learning disabilities, heart and other organ problems
Alcohol Consumption
Random
entirely preventable
Background risk:
one out of every 750 birthsFirst Cousins:
Consanguinity does not affect riskTreatment: Varies Because no amount of alcohol is proven safe, women should stop drinking immediately if they suspect that they might be pregnant. This refers to all types of alcohol, including wine, wine coolers, beer and mixed drinks.
Cleft Lip and Palate Failure of the cleft and/or the palate to close during during pregnancy causing facial disfiguration
Combination of genetic elements and environmental factors, such as drugs, infections, maternal illnesses, and possibly deficiency of folic acid Random, but mostly affecting Asians, American-Indians Background risk:
one out of every 930 birthsFirst Cousins: Consanguinity unlikely to cause an increase in risk
Risk is increased by mothers who smoke, abuse alchohol, or have diabetes.
Treatment: Surgery Toxoplasmosis
(causes stillbirth, hearing loss, hydrocephalus, mental retardation, learning disabilities, vision impairment or seizures)Can cause Cerebral Palsy
Parasitic Infection
(usually contracted from exposure to cat feces or eating undercooked meat)fetuses contract it from mothers
Random
60 to 85% of American women of childbearing age have never had toxoplasmosis and are susceptible to it during pregnancyBackground risk:
one out of every 1000 birthsFirst Cousins: Consanguinity does not affect risk
Screening: Maternal blood tests, amniocentesis Treatment: Post-natal antibiotics
Fragile X Syndrome
(intellectual disorders, ranging from mild learning disabilities to mental retardation)X-linked Random
Affects males, although women can be carriersBackground risk:
1 of every 1000 males
1 of every 700 females born are carriersFirst Cousins: Consanguinity unlikely to cause an increase in risk
Screening:
Molecular DNA testRh Disease
It is a hemolytic disease that causes destruction of fetal red blood cells. Can result in jaundice, anemia, brain damage, heart failure and death. It does not affect the mother’s health.Incompatibility between the blood of a mother and her fetus. Rarely affects first-born children
Random, but affects caucasions 2x more often than African-Americans.
Background risk:
one out of every 1,400 birthsFirst Cousins:
Consanguinity unlikely to cause an increase in riskScreening: amniocentesis, experimental tests Treatment:
Rhlg injections during pregnancy and postpartum; possible blood transfusion.Down’s Syndrome
Dwarfism, abnormal bone structure, learning disabilities, mental retardation, short life span
Chromosomal
Random
Mothers Age:
20: 1:10,000
35: 1:333
40: 1:100First Cousins: Consanguinity unlikely to cause an increase in risk
Screening: Amniocentesis or CVS
Spina Bifida
failure of the fetus’ spine to close properly during pregnancyCombination genetic and environmental only 5% of all spinal bifida disorders occur in families with previous history.
Hispanics, Whites of European descent
and occasionally other ethnic groupsBackground risk:
one out of every 2000 births
recurrance rate: 1:40First Cousins:
risk may be increased by 1.5% (1 of 1500 births)Screening: Prenatal Ultrasound or AFP Treatment: folic acid during pregnancy
Cystic Fibrosis
Excess production of unusually thick mucous, collecting in lungs. Can cause damage to pancreas. Shortened life-span.
Recessive Genetic, hereditary
Mostly Caucasion
Background risk
one out of every 2500 birthsFirst Cousins:
risk may double (2 out of every 2500 births)Screening:
Amniocentesis or CVS 90% accurate
Neurofibromatoses
The movie "Elephant Man" was about someone who had NF1
(also known as von Recklinghouasen’s disease {NF1}
and vestibular schwannoma {NF2})Dominant Genetic or Spontaneous gene mutation Random
Background risk: (NF1)
1 of every 4,000 birthsBackground risk: (NF2)
1 of every 40,000 birthsFirst Cousins: Consanguinity unlikely to cause an increase in risk
Treatment:
Medical proceedures can help minimize the problems associated wih NFHemophilia
("The Royal Family disease") Inability for blood to clot properly
X-linked
Random
Background risk:
1 of every 10,000 males (Men are rarely carriers as this is an X-linked disorder. Females rarely have the disorder, and if so the symptoms are much less severe)First Cousins: Consanguinity does’t increase the risk of hemophilia since only the mother is a carrier; the father is irrelevant.
Screening:
Genetic tests are available for parents and fetusesTreatment: Concentrated clotting factors can be administered at home.
Marfan Syndrome
variable pattern of abnormalities that may affect the heart, blood vessels, lungs, eyes, bones and ligamentsDominant Genetic / Chromosomal Random Background risk:
1 of every 10,000 birthsFirst Cousins: Consanguinity unlikely to cause an increase in risk
Screening:
None availablePKU (phenylketonuria)
Affects the way the body processes protein.
Causes mental retardation if left untreated
Recessive Genetic
Random,
but with highest occurance in Northern Europeans
Background Risk: 1 of every 12,000 births in U.S. First Cousins: consanguinity may increase risk by double (2 of every 12,000 births in U.S.)
Screening:
Standard post-natalTreatment:
Special diet low in phenylalanine, Nitric Oxide TherapyAchondroplasia
Abnormal bone growth, (affecting height)Chromosomal,
occasionally
Dominant GeneticOnly 20% of cases are inherited
Random
Background risk:
1 of every 26,000 birthsHighest risk: fathers over age 50
First Cousins: Consanguinity highly unlikely to cause an increase in risk
Screening:
highly accurate prenatal testing available
Muscular Dystrophy
Affects the central nervous system. Rarely diagnosed before age 12
Genetic, usually hereditary various forms include dominant genetic, recessive genetic, and x-linked.
Random
Severe types affect boys almost exclusively
Background Risk: Affects more than 300,000 people in the U.S., and 2,500,000 people worldwide First Cousins: Consanguinity unlikely to cause an increase in risk in dominant and x-linked forms, may increase risk in recessive forms of the disease.
Screening:
protein and DNA testing can rule out certain types of MS
Tay Sachs
loss of motor skills, blindness, inevitable death by age 5
Recessive Genetic
Jewish, French-Canadian
No stats on National Average, however: 30% of all Jews and French-Canadians are carriers. Two carriers have a 1:4 probability of having a child born with TaySachs.
First Cousins: greater probability of both cousins being carriers
Screening:
Amniocentesis or CVS
Thalassemia
Can cause anemia, organ enlargement, and pre- or post-natal death
Recessive Genetic
Italian, Greek, Middle Eastern, Southern Asian and African ancestry
100,000 infants worldwide First Cousins:
risk may be as much as 2x background risk.Screening: amniocentesis or CVS Treatment:
Blood transfusions + antibiotics
PKD
Only 50% of affected individuals experience problematic symptoms, including cysts on kidneys and liver, enlarged organs, and occasional Hiatal hernias or brain aneurysmsDominant Genetic
Random
500,000 cases in US, rarely affecting infants First Cousins: Consanguinity unlikely to cause an increase in risk
Screening: Available for pre-natal and adults Treatment: General physical and nutritional health, in some cases dialysis or kidney transplant is recommended
Other problems which commonly cause birth defects are:
- Cocain use during pregnancy (affects 45,000 babies each year in the U.S.) can cause stroke, brain damage, prenatal addiction, death
- STD’s: Syphillis affects 1:2,000 newborns, and 1:2,700 babies are born HIV+ each year. Over 500,000 new cases of Genital Herpes occur each year, including about 1,000 in newborn babies.
- Medicinal drugs, including Thalidomide, Accutane and other retinoids, and ingredients in many common over the counter medications have been responsible for tens of thousands of birth defects ranging from mild facial distortions, to missing limbs, and even death in recent decades.
This is by no means an all-inclusive list! There are between three and five thousand known birth defects, affecting 150,000 babies each year. Sixty percent of all birth defects have unknown causes. According to the Centre for Human Genetics, and the NSGC, every couple has approximately a 3% risk of having a child with a birth defect. This risk is additionally increased by 1.5 to 3% for children born to first cousins. Little, if any increased risk exists for more distantly related individuals.Dominant Genetic: One affected parent has a single faulty gene (D) which dominates its normal counterpart (d). Each child produced has a 50% risk of inheriting the D, and the disorder from the affected parent. If both parents have the faulty gene, each child has a 75% risk of inheriting the disorder.
X-Linked Genetic: Passed on only through the mother. The mother, who has a defective gene on one of her two sex chromosomes, is protected against the defect because her normal sex chromosome (x) compensates for the defect on the other (X). The father has normal male sex chromosomes (x and y). Each male child has a 50% risk of inheriting the faulty X, and the disorder, and a 50% chance of inheriting the normal x chromosome. Each female child has a 50% risk of inheriting the faulty X and becoming a carrier like her mother, and a 50% chance of inheriting two normal X chromosomes.
Recessive Genetic: Both parents, usually unaffected, carry a defective gene (g) but are protected by the presence of a normal gene (G) which is generally sufficient for normal function. Each child produced has a 25% risk of inheriting a double dose of the g gene, which may cause a serious genetic defect; a 25% chance of inheriting two normal genes; and a 50% chance of being a carrier like both parents.
Sources:
March Of Dimes,
Imaginis Women’s Health Network,
Yale-New Haven Teacher’s Institute,
The Polycystic Kidney Research FoundationGO TO PAGE 3 OF THE OVERVIEW –>
© 2000 Christie Schuler Smith for CUDDLE International and cousincouples.org