Quantcast
4S Ranch Allied Gardens Alpine Baja Balboa Park Bankers Hill Barrio Logan Bay Ho Bay Park Black Mountain Ranch Blossom Valley Bonita Bonsall Borrego Springs Boulevard Campo Cardiff-by-the-Sea Carlsbad Carmel Mountain Carmel Valley Chollas View Chula Vista City College City Heights Clairemont College Area Coronado CSU San Marcos Cuyamaca College Del Cerro Del Mar Descanso Downtown San Diego Eastlake East Village El Cajon Emerald Hills Encanto Encinitas Escondido Fallbrook Fletcher Hills Golden Hill Grant Hill Grantville Grossmont College Guatay Harbor Island Hillcrest Imperial Beach Imperial Valley Jacumba Jamacha-Lomita Jamul Julian Kearny Mesa Kensington La Jolla Lakeside La Mesa Lemon Grove Leucadia Liberty Station Lincoln Acres Lincoln Park Linda Vista Little Italy Logan Heights Mesa College Midway District MiraCosta College Miramar Miramar College Mira Mesa Mission Beach Mission Hills Mission Valley Mountain View Mount Hope Mount Laguna National City Nestor Normal Heights North Park Oak Park Ocean Beach Oceanside Old Town Otay Mesa Pacific Beach Pala Palomar College Palomar Mountain Paradise Hills Pauma Valley Pine Valley Point Loma Point Loma Nazarene Potrero Poway Rainbow Ramona Rancho Bernardo Rancho Penasquitos Rancho San Diego Rancho Santa Fe Rolando San Carlos San Marcos San Onofre Santa Ysabel Santee San Ysidro Scripps Ranch SDSU Serra Mesa Shelltown Shelter Island Sherman Heights Skyline Solana Beach Sorrento Valley Southcrest South Park Southwestern College Spring Valley Stockton Talmadge Temecula Tierrasanta Tijuana UCSD University City University Heights USD Valencia Park Valley Center Vista Warner Springs

Genetic Screening

My friend Sasha is type A; she always has her ducks in a row. She's been married for several years now and is thinking of starting a family. She's read a slew of books on pregnancy and child-rearing. I think there's such a thing as too much information; Sasha disagrees. So I wasn't surprised when she asked what I knew about genetic screening. Not much, I said, but I promised I'd look into it.

My promise took me to Thornton Hospital in La Jolla. I spoke with genetic counselor Jason Chibuk, whose specialty is prenatal diagnosis. Sasha would have liked him. "The best time for people to come in if they're thinking of having children is preconception. That way, there's not the forced timeframe of making decisions while the pregnancy is ongoing."

Chibuk said that "the first and most important part of genetic screening is to sit down with someone trained in genetics and assess the family history. Genetics, more than any other specialty in medicine, focuses not only on the patient, but also on the family as a whole, for predicting the likelihood of disease. Then, if this history indicates that genetic testing is warranted, we're able to do tests. We do a three-generation pedigree, in which we're looking at siblings and parents, aunts and uncles, and grandparents for the individual at risk. So there's the cancer genetics realm, the pediatric and adult genetics realm, and the prenatal genetics realm."

A primary care physician makes the determination if a person's family history of cancer has some genetic background, said Chibuk. "Breast and ovarian cancers and colon cancers at a young age may arise from a genetic disposition that can be tested for. Then, other at-risk family members can be given appropriate reoccurrence risks. There are some women who may be at risk for ovarian cancer, and they may choose, once they're done with their childbearing years, to have their ovaries removed, instead of seeing whether the cancer strikes or not." When it comes to pediatric genetic diseases, "generally, once an affected individual comes to light, we can begin to look at the individual, look at his family history, and start analyzing. 'How did this happen?' That way, they can determine care for the individual and recurrence risks for the other family members."

In prenatal diagnosis, "there are many different types of screenings, including those done based on family history, ethnic background, blood testing, or ultrasound findings." He zeroed in on ethnic background. "Different ethnic backgrounds have elevated risks to be carriers for different genetic diseases. One in 25 Caucasians is a carrier for cystic fibrosis, a chronic lung disorder. In the African-American population, one in 10 persons is a carrier for sickle cell disease. It doesn't harm you to be a carrier, so in most circumstances you wouldn't know it if you were. But if both Mom and Dad are carriers, then the baby is at risk; there's a one-in-four chance that the baby will have the disease. There's a one-in-two chance that the baby will be a carrier. And there's a one-in-four chance that the baby is neither affected nor a carrier."

Testing is done through blood work; the nature of the test depends on what you're looking for. Chibuk took cystic fibrosis as an example. "In this case, you're looking at the CFTR gene and analyzing it for 30 of the most common mutations. A mutation is a sequence alteration within a gene that leads to the gene being unable to produce a functional gene product, or protein. The human genome is like 46 textbooks -- the chromosomes -- of genetic information. Each chromosome contains several chapters -- several genes. We read through a chapter, or a certain sentence in that chapter, where we know that spelling errors -- mutations -- are common. In the case of cystic fibrosis, there are 30 spelling errors that make up 90 percent of all the known mutations of the gene responsible and which lead to the disease." If both parents are carriers, "we might get into tests in utero, doing fetal diagnosis through a biopsy of the placenta, or through amniocentesis." (Of course, there's still the remaining 10 percent, which means that you could still be a carrier -- but it's far less likely. Added Chibuk, "With a negative test result for cystic fibrosis in a Caucasian, the risk of being a carrier is reduced from 1-in-25 to 1-in-240.")

"We offer cystic fibrosis carrier screening to all pregnant couples, or couples planning pregnancy," continued Chibuk. If ethnic background indicates the need for testing, he supposes that it will be covered by insurance. "A cystic fibrosis screening at UCSD is $150; a screening for sickle-cell disease is around $50. But those don't screen for everything. In a prenatal diagnosis, once you start doing ultrasound and amniocentesis, and then looking at the chromosomes and screening for things like Down syndrome, you're looking at a bill over $1000 [without insurance]."

After the screening, Chibuk's job is to relay the information to the patients and to act as a support if the information turns out to be stressful. "Defining the severity of a genetic disease is a difficult thing," he noted. "Cystic fibrosis is not a life-threatening condition. There is no mental retardation, and there are no clinical physical changes. In contrast, Trisomy 18 is a condition in which the baby has three copies of chromosome 18 -- we're supposed to have two. The life span of a baby with Trisomy 18 is not expected to exceed a year." Based on the information, some people may choose to abort ("which is a legal option in San Diego County through the 23rd week"), some give up their babies for special-needs adoption. "Some people just want to be prepared, to learn about the condition so they can be ready for it when the child arrives," continued Chibuk, and pregnancy is when he'd most like to see a couple.

Here's something you might be interested in.
Submit a free classified
or view all

Previous article

North Park – the prime quartier

30th Street parking, Georgia Street bridge, PSA crash, water tower, North Park Main Street
Next Article

Angry Pete's Pizza brings Detroit to Kensington

Thick crust and caramelized cheese will make you forget about round pies

My friend Sasha is type A; she always has her ducks in a row. She's been married for several years now and is thinking of starting a family. She's read a slew of books on pregnancy and child-rearing. I think there's such a thing as too much information; Sasha disagrees. So I wasn't surprised when she asked what I knew about genetic screening. Not much, I said, but I promised I'd look into it.

My promise took me to Thornton Hospital in La Jolla. I spoke with genetic counselor Jason Chibuk, whose specialty is prenatal diagnosis. Sasha would have liked him. "The best time for people to come in if they're thinking of having children is preconception. That way, there's not the forced timeframe of making decisions while the pregnancy is ongoing."

Chibuk said that "the first and most important part of genetic screening is to sit down with someone trained in genetics and assess the family history. Genetics, more than any other specialty in medicine, focuses not only on the patient, but also on the family as a whole, for predicting the likelihood of disease. Then, if this history indicates that genetic testing is warranted, we're able to do tests. We do a three-generation pedigree, in which we're looking at siblings and parents, aunts and uncles, and grandparents for the individual at risk. So there's the cancer genetics realm, the pediatric and adult genetics realm, and the prenatal genetics realm."

A primary care physician makes the determination if a person's family history of cancer has some genetic background, said Chibuk. "Breast and ovarian cancers and colon cancers at a young age may arise from a genetic disposition that can be tested for. Then, other at-risk family members can be given appropriate reoccurrence risks. There are some women who may be at risk for ovarian cancer, and they may choose, once they're done with their childbearing years, to have their ovaries removed, instead of seeing whether the cancer strikes or not." When it comes to pediatric genetic diseases, "generally, once an affected individual comes to light, we can begin to look at the individual, look at his family history, and start analyzing. 'How did this happen?' That way, they can determine care for the individual and recurrence risks for the other family members."

In prenatal diagnosis, "there are many different types of screenings, including those done based on family history, ethnic background, blood testing, or ultrasound findings." He zeroed in on ethnic background. "Different ethnic backgrounds have elevated risks to be carriers for different genetic diseases. One in 25 Caucasians is a carrier for cystic fibrosis, a chronic lung disorder. In the African-American population, one in 10 persons is a carrier for sickle cell disease. It doesn't harm you to be a carrier, so in most circumstances you wouldn't know it if you were. But if both Mom and Dad are carriers, then the baby is at risk; there's a one-in-four chance that the baby will have the disease. There's a one-in-two chance that the baby will be a carrier. And there's a one-in-four chance that the baby is neither affected nor a carrier."

Testing is done through blood work; the nature of the test depends on what you're looking for. Chibuk took cystic fibrosis as an example. "In this case, you're looking at the CFTR gene and analyzing it for 30 of the most common mutations. A mutation is a sequence alteration within a gene that leads to the gene being unable to produce a functional gene product, or protein. The human genome is like 46 textbooks -- the chromosomes -- of genetic information. Each chromosome contains several chapters -- several genes. We read through a chapter, or a certain sentence in that chapter, where we know that spelling errors -- mutations -- are common. In the case of cystic fibrosis, there are 30 spelling errors that make up 90 percent of all the known mutations of the gene responsible and which lead to the disease." If both parents are carriers, "we might get into tests in utero, doing fetal diagnosis through a biopsy of the placenta, or through amniocentesis." (Of course, there's still the remaining 10 percent, which means that you could still be a carrier -- but it's far less likely. Added Chibuk, "With a negative test result for cystic fibrosis in a Caucasian, the risk of being a carrier is reduced from 1-in-25 to 1-in-240.")

"We offer cystic fibrosis carrier screening to all pregnant couples, or couples planning pregnancy," continued Chibuk. If ethnic background indicates the need for testing, he supposes that it will be covered by insurance. "A cystic fibrosis screening at UCSD is $150; a screening for sickle-cell disease is around $50. But those don't screen for everything. In a prenatal diagnosis, once you start doing ultrasound and amniocentesis, and then looking at the chromosomes and screening for things like Down syndrome, you're looking at a bill over $1000 [without insurance]."

After the screening, Chibuk's job is to relay the information to the patients and to act as a support if the information turns out to be stressful. "Defining the severity of a genetic disease is a difficult thing," he noted. "Cystic fibrosis is not a life-threatening condition. There is no mental retardation, and there are no clinical physical changes. In contrast, Trisomy 18 is a condition in which the baby has three copies of chromosome 18 -- we're supposed to have two. The life span of a baby with Trisomy 18 is not expected to exceed a year." Based on the information, some people may choose to abort ("which is a legal option in San Diego County through the 23rd week"), some give up their babies for special-needs adoption. "Some people just want to be prepared, to learn about the condition so they can be ready for it when the child arrives," continued Chibuk, and pregnancy is when he'd most like to see a couple.

Sponsored
Here's something you might be interested in.
Submit a free classified
or view all
Previous article

The Longview Manor estate built by Ralph Hurlburt

He designed dozens of distinctive houses from Point Loma to Kensington to La Mesa
Next Article

Ocean Beach trash altruist

Cameron Reid covers Niagara and Narragansett, Sunset Cliffs to Abbott.
Comments
0

Be the first to leave a comment.

Sign in to comment

Sign in

Art Reviews — W.S. Di Piero's eye on exhibits Ask a Hipster — Advice you didn't know you needed Best Buys — San Diego shopping Big Screen — Movie commentary Blurt — Music's inside track Booze News — San Diego spirits City Lights — News and politics Classical Music — Immortal beauty Classifieds — Free and easy Cover Stories — Front-page features Excerpts — Literary and spiritual excerpts Famous Former Neighbors — Next-door celebs Feast! — Food & drink reviews Feature Stories — Local news & stories From the Archives — Spotlight on the past Golden Dreams — Talk of the town Here's the Deal — Chad Deal's watering holes Just Announced — The scoop on shows Letters — Our inbox [email protected] — Local movie buffs share favorites Movie Reviews — Our critics' picks and pans Musician Interviews — Up close with local artists Neighborhood News from Stringers — Hyperlocal news News Ticker — News & politics Obermeyer — San Diego politics illustrated Of Note — Concert picks Out & About — What's Happening Overheard in San Diego — Eavesdropping illustrated Poetry — The old and the new Pour Over — Grab a cup Reader Travel — Travel section built by travelers Reading — The hunt for intellectuals Roam-O-Rama — SoCal's best hiking/biking trails San Diego Beer News — Inside San Diego suds SD on the QT — Almost factual news Set 'em Up Joe — Bartenders' drink recipes Sheep and Goats — Places of worship Special Issues — The best of Sports — Athletics without gush Street Style — San Diego streets have style Suit Up — Fashion tips for dudes Theater Reviews — Local productions Theater antireviews — Narrow your search Tin Fork — Silver spoon alternative Under the Radar — Matt Potter's undercover work Unforgettable — Long-ago San Diego Unreal Estate — San Diego's priciest pads Waterfront — All things ocean Your Week — Daily event picks
4S Ranch Allied Gardens Alpine Baja Balboa Park Bankers Hill Barrio Logan Bay Ho Bay Park Black Mountain Ranch Blossom Valley Bonita Bonsall Borrego Springs Boulevard Campo Cardiff-by-the-Sea Carlsbad Carmel Mountain Carmel Valley Chollas View Chula Vista City College City Heights Clairemont College Area Coronado CSU San Marcos Cuyamaca College Del Cerro Del Mar Descanso Downtown San Diego Eastlake East Village El Cajon Emerald Hills Encanto Encinitas Escondido Fallbrook Fletcher Hills Golden Hill Grant Hill Grantville Grossmont College Guatay Harbor Island Hillcrest Imperial Beach Imperial Valley Jacumba Jamacha-Lomita Jamul Julian Kearny Mesa Kensington La Jolla Lakeside La Mesa Lemon Grove Leucadia Liberty Station Lincoln Acres Lincoln Park Linda Vista Little Italy Logan Heights Mesa College Midway District MiraCosta College Miramar Miramar College Mira Mesa Mission Beach Mission Hills Mission Valley Mountain View Mount Hope Mount Laguna National City Nestor Normal Heights North Park Oak Park Ocean Beach Oceanside Old Town Otay Mesa Pacific Beach Pala Palomar College Palomar Mountain Paradise Hills Pauma Valley Pine Valley Point Loma Point Loma Nazarene Potrero Poway Rainbow Ramona Rancho Bernardo Rancho Penasquitos Rancho San Diego Rancho Santa Fe Rolando San Carlos San Marcos San Onofre Santa Ysabel Santee San Ysidro Scripps Ranch SDSU Serra Mesa Shelltown Shelter Island Sherman Heights Skyline Solana Beach Sorrento Valley Southcrest South Park Southwestern College Spring Valley Stockton Talmadge Temecula Tierrasanta Tijuana UCSD University City University Heights USD Valencia Park Valley Center Vista Warner Springs
Close