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Jordanna Joaquina, MS, CGC  
Female

Interests: Prenatal Genetics, Pediatric Genetics

AccessDNA
Los Angeles, CA
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What Every Expecting Parent Should Know About Genetic Testing

Oct 26, 2009 - 6 comments
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genetic testing

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genetic

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DNA

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genes

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genetic disorders

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genetic disease

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genetic diseases



So you’re pregnant…time to celebrate!  But how to celebrate when you’re told your pregnancy could be affected by countless disorders, with names you can't even pronounce?

Thankfully, most babies are born healthy.  There are, however, a number of reasons you may want to speak with a genetic counselor (a medical professional trained in assessing the risk for birth defects and genetic disorders) before or during your pregnancy.  Some more common reasons include:

* Maternal age
* A family history of a condition
* Ethnic-based carrier testing

Maternal Age
As women age their eggs age and, consequently, so does their risk of having a child with a chromosomal abnormality.  Down syndrome (also known as Trisomy 21) is the most common chromosomal abnormality and people with Down syndrome have varying degrees of mental retardation and physical birth defects.  A woman’s estimated risk of having a child with Down syndrome is:

* At age 25, 1 in 1,250
* At age 30, 1 in 952
* At age 35, 1 in 385
* At age 40, 1 in 106
* At 45, 1 in 30
* At 49, a 1 in 11

Nevertheless, in 2007 the American College of Obstetrics and Gynecology (ACOG) recommended that all pregnant women, regardless of age, be offered screening for Down syndrome, as well as the option of diagnostic testing.  Diagnostic testing can tell with greater than 99% accuracy whether or not a pregnancy is affected with Down syndrome, Trisomy 18 and other chromosomal abnormalities, as well as certain genetic diseases (if indicated).

For more information on screening and diagnostic testing options during pregnancy, visit:
http://www.AccessDNA.com/condition/Genetic_Testing_in_Pregnancy/668

History of Genetic Disorder (or Conditions Associated with a Genetic Disorder)
Family history is one of the most important tools in assessing the risk for a birth defect and/or genetic disorder.  The risks of having an affected child is condition specific, but may depend on multiple factors such as the inheritance pattern of the disorder, the degree of the relationship of affected family members (i.e., first degree, second degree, etc.) and the gender and number of affected relatives.  

A family history of any of the following conditions (and many more not listed) may warrant seeing a genetic counselor:

* Chromosomal abnormalities (such as Down syndrome, Trisomy 13, etc.
* Muscular dystrophy
* Neurofibromatosis
* Seizures
* Recurrent miscarriages (two or more)
* Fertility problems
* Ashkenazi Jewish disorders (such as Tay-Sachs disease, Canavan disease, etc.)
* Hemophilia and other bleeding disorders
* Cystic fibrosis
* Huntington’s disease
* Mental retardation
* Autism
* Birth defects (such as spina bifida, congenital heart defects, etc.)

To find detailed information on a specific genetic condition, visit: http://www.AccessDNA.com/Genetic_Education_and_Information

Ethnic-Based Carrier Testing
Some genetic disorders, such as sickle cell disease, Tay-Sachs disease, thalassemia and cystic fibrosis, occur more frequently in people of certain ethnic backgrounds. Many of these conditions are inherited in an autosomal recessive pattern, which means two copies of a mutated gene, one from each parent, are necessary to cause the disorder. People with only one copy of a mutated gene are known as carriers. In most autosomal recessive conditions, carriers do not have any symptoms of the condition and, therefore, are often unaware that they are a carrier.

In the absence of a known family history of such disorders, the risk of being a carrier is based on a person’s ethnic background.  The risk of having a child with such disorders is based on the inheritance pattern, as well as both of the parent’s ethnic backgrounds.  As such, couples who are of the same ethnic background may have a higher risk of having a child with autosomal recessive disorders than couples who are of different ethnic backgrounds.  Couples who are related to each other by blood, such as cousins, may have an even higher risk.

Carrier testing is currently available for many autosomal recessive conditions if indicated by ethnic background.  Testing is typically performed on a blood sample, but in some cases, can be performed on cheek cells obtained from a cheek swab or saliva sample.

For more information on patterns of genetic inheritance, visit: http://www.AccessDNA.com/condition/Patterns_of_Inheritance/253

What Happens in a Genetic Counseling Session
A genetic counselor will need to know medical information about you and your family and may begin by constructing a family medical tree, called a pedigree.  This pedigree maps out the relationships between three generations of your relatives and will include information such as pregnancy information, major health conditions, known genetic disorders, age of disease diagnosis, lifestyle factors and ethnicity.

For more information on what happens in a genetic counselor session, visit:
http://www.AccessDNA.com/condition/Genetic_Consultation/392


Health2.0 Conference

Oct 12, 2009 - 1 comments
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health2.0 conference

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Medicine

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Health



The theme of this year’s Health2.0 Conference last week in San Francisco, CA was not personalized medicine but rather how to personalize medicine. Over 200 companies attended, from small start-ups to big pharma, showcasing the latest and greatest web-based and mobile innovations in healthcare.

The products that appeared to create the most buzz were aimed at decreasing barriers to quality patient care, while at the same time, engaging patients in participatory medicine. The main stage and break-out sessions featured not only product demos but also discussions with many of the high-up executives associated with them.

For more visit: http://blog.accessdna.com/?p=50

DTC Genetic Testing as an Effective Motivator?

Oct 12, 2009 - 0 comments
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Health

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Medicine

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Genetics

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genetic disease

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direct to consumer genetic

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DTC genetic testing



Laura Hercher, MS, CGC did a wonderful job summarizing some of the main points of discussion at the two-day workshop on direct-to-consumer (DTC) genetic testing, which was co-sponsored by the Institute of Medicine and the National Academy of Science at The DNA Exchange (http://dnaexchange.wordpress.com/2009/09/04/dc-takes-on-dtc-the-t-doesnt-stand-for-tomorrow-anymore/).

As a follow-up, I would like to touch upon a point to which the represented DTC companies alluded a few times, as did some of the speakers: the use of direct-to-consumer genetic test results as an effective motivator for lifestyle change.

Most health professionals probably agree that there is limited clinical utility to most single nucleotide polymorphism (SNP) tests at this time. At most, they may argue, test results are informational but not medically relevant.

However, as DTC companies and other groups race to validate these SNPs as a better (or at least appropriate) indicator for multifactorial disease, I also wonder whether test results will also motivate individuals to make healthier choices and engage in proactive, preventative medicine.

For more visit: http://blog.accessdna.com/?p=9

The Genetics of Asthma

Jul 08, 2009 - 0 comments
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Genetics

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asthma genetics

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asthma medications

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inheritance of asthma

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asthma genes

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asthma in families



The causes of asthma are largely unknown. Asthma is most likely a multifactorial condition, which means it involves a combination of genetic, lifestyle and environmental factors.

Some non-genetic factors that have been proposed to increase susceptibility to asthma include having recurrent childhood respiratory infections, secondhand smoke exposure, low birth weight, being overweight, living in an urban area, and exposure to certain chemicals (such as chemicals used in farming, manufacturing, and hairdressing).

It is currently well established that asthma also runs in some families. Researchers believe that there are probably a number of genes that affect the development and symptoms of asthma as well as affect a person's response to certain asthma medications.

Variations in many genes have been identified in some families, but no one gene has been strongly associated with asthma.  

Variations in the ADRB2 gene have been associated with asthma susceptibility. In addition, a particular variation (arg16) in the ADRB2 gene has been shown in several studies to alter the body's response to beta-agonists, a type of medication used to treat asthma. Beta-agonists include albuterol, salbutamol, and salmeterol. We all have two copies of the ADRB2 gene. A little less than 20% of the U.S. general population has two copies of this variation, one in each gene. The effectiveness of albuterol as a rescue therapy may be reduced in these individuals when beta-agonists are used as a routine treatment for asthma.

Single nucleotide polymorphisms (SNPs) are small variations in a single "letter" of DNA that can be found throughout our entire genetic make-up. Some researchers have proposed that specific SNPs may influence the risk to develop asthma in some people. How (or whether) many of these SNPs contribute to asthma is still unclear. Research is currently often limited to specific ethnic groups. Further research is needed to replicate study findings across different ethnic groups and clearly establish associations.

Other yet to be identified or adequately classified genes may also contribute to asthma.

For more information on the genetics and inheritance of asthma, visit: http://AccessDNA.com/condition/Asthma/409