Tag Archives: pediatrics

DNA test for congenital cataracts leads to faster, more accurate diagnoses of rare diseases linked to childhood blindness

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Ophthalmology_Pediatrics

Researchers in the United Kingdom have demonstrated that advanced DNA testing for congenital cataracts can quickly and accurately diagnose a number of rare diseases marked by childhood blindness, according to a study published online in Ophthalmology, the journal of the American Academy of Ophthalmology. Using a single test, doctors were able to tailor care specifically to a child’s condition based on their mutations reducing the time and money spent on diagnosis and enabling earlier treatment and genetic counseling.

Each year, between 20,000 and 40,000 children worldwide are born with congenital cataracts, a disease that clouds the lens of the eye and often requires surgery and treatment to prevent blindness.[1] The disease can arise following a maternal infection or be inherited as an isolated abnormality. Congenital cataracts can also appear as a symptom of more than 100 rare diseases, making mutations in the 115 genes associated with congenital cataracts useful as diagnostic markers for the illnesses.

Diagnosing these rare diseases previously proved a lengthy, costly and inconclusive process involving numerous clinical assessments and taking a detailed family history. DNA testing, one gene at a time, would have taken years to complete. Employing new DNA sequencing technology, called targeted next-generation sequencing, researchers at the University of Manchester sped up diagnosis to a matter of weeks by testing for mutations in all 115 known congenital cataracts genes at one time.

In 75 percent of the 36 cases tested, the DNA test determined the exact genetic cause of congenital cataracts. In one case, the DNA test helped diagnose a patient with Warburg Micro syndrome, an extremely rare disease that is marked by an abnormally small head and the development of severe epilepsy, among other medical issues. Having a clear diagnosis allowed for genetic counseling and appropriate care to be delivered quicker than previously possible without the test.

“There are many diseases that involve congenital cataracts but finding the exact reason was always difficult,” said Graeme Black, DPhil., professor of genetics and ophthalmology at the University of Manchester and strategic director of the Manchester Centre for Genomic Medicine. “Even with a family history, diagnosing these rare diseases was always a bit of a shot in the dark.”

In the course of their work, done in collaboration with Manchester Royal Eye Hospital, researchers also found previously undescribed mutations linked to cataract formation. “There is hope that our work may one day provide more insight into the development and treatment of age-related cataracts, a leading cause of blindness worldwide,” said Rachel Gillespie, MSc, lead author of the study who designed and developed the test.

The test was made available to U.K. patients through the country’s National Health Service in December 2013. Infants and children who have congenital cataracts can be tested as well as prospective parents with a history of the condition who wish to evaluate the risk to their child. Results generally take about two months. While only available in the U.K., the congenital cataract DNA test can be requested by registered medical facilities through international referral.

As with all genetic testing, the American Academy of Ophthalmology encourages clinicians and patients to consider the benefits as well as the risks. Ophthalmologists who order genetic tests either should provide genetic counseling to their patients themselves, if qualified to do so, or should ensure that counseling is provided by a trained individual, such as a board-certified medical geneticist or genetic counselor. For more information, please see the Academy’s recommendations on genetic testing for inherited eye diseases.

 

http://www.medicalnewstoday.com/releases/281442.php

 

 

 

GPs urged to ensure every squint is checked with a red reflex test to rule out eye cancer

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May_Part 1_Ophthalmology_Pediatrics

A children’s cancer charity is calling for all squints in babies and young children to be checked with a red reflex test to rule out eye cancer.

Figures released from the Childhood Eye Cancer Trust (CHECT) show that in 2013, over a quarter (26%) of babies and young children diagnosed with retinoblastoma (Rb) presented with a squint as a symptom.1 It is the second most common symptom after leukocoria (white pupillary reflex).

Joy Felgate, Chief Executive of CHECT said: “In our experience, some babies and young children are facing serious delays in receiving life-saving treatment as a result of parents either being told incorrectly that their baby’s squint is completely normal, or being given a non-urgent squint referral.”

Katy Bishop’s son Owen was incorrectly referred to a squint clinic at five months of age. His bilateral retinoblastoma was not diagnosed until he was ten months old. “Owen was too young to tell me his vision was failing, and his diagnosis was delayed five months because his squint was not properly checked. By the time he was diagnosed, he had a detached retina and was borderline for enucleation. Since then, he has had chemotherapy, cryotherapy and blood transfusions. We will never know the impact that five months’ delay has had on Owen’s future.”

As squints are common in babies up to the age of three months, the only way to determine whether this is a sign of a much more serious condition is to carry out a simple red reflex test, which is a non-invasive procedure, simply involving looking in the eye with a hand-held ophthalmoscope.

Mrs Felgate continued: “Non-urgent squint referrals can take months to come through, which can be a devastating delay for a child with undiagnosed eye cancer. Retinoblastoma is a very aggressive form of cancer and any delays in diagnosis can have a serious impact on treatment options. Currently more than 70% of children with unilateral Rb lose an eye to the disease.

“We are asking GPs to check every squint they see with the red reflex test.”

To promote this message CHECT has developed e-cards and an email campaign that GPs can share and forward on to colleagues. Copies of these are available from info@chect.org.uk.

Retinoblastoma is a fast-growing cancer of the eye affecting mainly 0 to 5-year-old children. Early detection of this aggressive condition is crucial to offer the child the best chance of saving their vision, their eyes and their life.

CHECT urges GPs to pay particular attention to children with

  • A recently onset squint
  • A white reflex (leukocoria) or an abnormal reflex in flash photographs
  • A change in colour to the iris
  • A deterioration in vision

Occasionally a retinoblastoma may present as a red, sore or swollen eye without infection. It is important to remember, however, that a child with Rb may appear systemically well.

Following a successful campaign by CHECT, most of these symptoms are now also listed in the latest versions of the Public Child Health Record (red book).

If any of the above symptoms are detected, a simple red reflex test can rule out retinoblastoma.

If you are unable to confidently rule out retinoblastoma with a red reflex test NICE guidelines state an urgent referral must be made to the local ophthalmology department stating ‘suspected retinoblastoma’. We recommend you call to alert them to the case and to find out how quickly urgent referrals are seen (in some cases it can be longer than two weeks).

http://www.medicalnewstoday.com/releases/276723.php

 

White Boys More Likely to Be Color Blind

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April_Part 2_Ophthalmology

 

Color blindness is not colorblind, as it appears to afflict Caucasian boys at three times the rate of African-American boys, according to a new study.

Among children 37 to 72 months of age, a total of 5.6% of Caucasian boys had color blindness compared with 1.6% of African-American boys, reported Rohit Varma, MD, MPH, of the University of Illinois at Chicago, and colleagues.

Asian boys had the second highest percentage at 3.1%, followed by Hispanic boys with 2.6%, they reported online in Ophthalmology.

The overall prevalence of color blindness was about 2% — translating to 59 boys and four girls out of 4,005 children who were able to complete the test. Color blindness is generally much more common in boys than in girls, since the red and green pigment genes involved in color vision are located on the X chromosome.

“To our knowledge, no previous population-based studies have investigated the prevalence of color vision deficiency in a multi-ethnic cohort of preschool children younger than 6 years,” researchers said.

Lore Nelson, MD, a pediatrician with the The University of Kansas Hospital in Kansas City, Kan., told MedPage Today that the study confirms what she and her colleagues see in clinical practice.

“The study is a reminder to screen more closely those groups with a higher incidence of color blindness,” she said.

The recommended age to begin vision screening — 3 years — is endorsed by the American Academy of Pediatrics, the American Academy of Ophthalmology, and the American Association for Pediatric Ophthalmology and Strabismus.

For their analysis, Varma and colleagues recruited the children from Los Angeles and Riverside counties in California as part of the population-based Multi-Ethnic Pediatric Eye Disease Study (MEPEDS).

When researchers compared older (61 to 72 months) with younger (37 to 60 months) children, they found no difference in prevalence of color blindness, nor did they find a difference between younger and older kids within any ethnic group.

They noted that testability was high by the age of 4 and increased linearly with age:

  • Ages 30 to 36 months: 17% were testable
  • Ages 37 to 48 months: 57%
  • Ages 49 to 60 months: 89%
  • Ages 61 to 72 months: 98%

The divide along ethnic lines is also reflective of findings in older children, Varma and colleagues pointed out. Data from the CDC’s National Health Examination Survey from the early 1960s found a 3.8% overall prevalence of color blindness in children ages 6 to 11 years(about 900,000 children affected). Among boys, race appeared to be significantly related to the presence of color blindness: 7.4% for whites versus 4% for blacks.

The corresponding study in children 12 to 17 years conducted in the latter half of the 1960s found an overall prevalence of 4.3% (again about 900,000 children affected), but the difference between white and black boys was not significant (7.7% versus 6.4%).

An earlier collaboration between MEPEDS and the the Baltimore Pediatric Eye Disease Study (BPEDS) also found ethnic differences regarding myopia and hyperopia.

Varma and colleagues noted that their study has some strengths, including “the large MEPEDS population-based cohort and the fact that standardized color vision testing was administered to the children by eye care professionals.”

Image courtesy of https://www.facebook.com/ResearchtoPreventBlindness

http://www.medpagetoday.com/Pediatrics/GeneralPediatrics/45100

 

 

 

Early detection of childhood eye cancer doesn’t always improve survival, prevent eye loss

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Oncology_Pediatrics_Ophthalmology

For the most common form of childhood eye cancer, unilateral retinoblastoma, shortening the time from the first appearance of symptoms to diagnosis of disease has no bearing on survival or stage of the disease, according to a study by researchers at Columbia University Mailman School of Public Health in partnership with the Hospital Infantil de Mexico. The results appear online in the journal Cancer Epidemiology, Biomarkers & Prevention.

Because retinoblastoma is easily detectable by shining a light into a child’s eye – often as a “cat’s eye” reflection revealed through flash photography – a number of countries, particularly resource-poor countries where the disease is more prevalent, have initiated education and screening programs, thinking that catching the disease early would lead to improved outcomes. This study is the first to follow a cohort of children with the disease over time and to look at the unilateral (one eye) and bilateral (two eyes) forms of the disease separately.

“Our study suggests that screening children for retinoblastoma may not improve outcomes for the majority of patients, particularly for the more common form of the disease affecting one eye,” says senior author Manuela A. Orjuela, MD, ScM, assistant professor of pediatrics and environmental health sciences at Columbia University Medical Center. “By the time the tumoris visible in the child’s eye, vision is infrequently salvageable, and removal of the eye is usually necessary to prevent spread of the disease.”

The research team followed 179 children with retinoblastoma in Mexico City and interviewed their parents about symptoms and socio-demographic factors. Physicians at the Hospital Infantil de México assessed disease stage using several validated methods. The researchers found that for unilateral disease, the lag-time between when parents first noticed the disease and when the children were diagnosed had no bearing on disease stage or survival. In the rarer bilateral disease, a longer lag-time was strongly associated with a more advanced stage and worse survival, but it did not predict the extent of disease involvement in the more affected eye. Lag-times averaged seven and eight months for unilateral and bilateral disease, respectively.

“Retinoblastoma is usually thought of as one disease. But there is good evidence that unilateral and bilateral retinoblastoma are distinct and progress in different ways,” says Dr. Orjuela.

“There is also significant variation in how tumors respond to treatment, no matter how soon we initiate therapy,” says first author Marco A. Ramírez-Ortiz, MD, chief of the department of Ophthalmology at the Hospital Infantil de México Federico Gomez, Mexico City.

Education and Housing Conditions Predict Outcomes

Intriguingly, the researchers found that stage and survival in both forms of retinoblastoma were predicted by the mother’s education level. Mothers with less formal schooling had children with significantly higher stage disease and significantly worse survival. Education was more important than the time needed for families to travel to the hospital or how many other young children needing childcare were in the household.

The child’s home environment may be another contributing factor. Children born in homes with dirt floors had more advanced disease than their peers with different housing conditions, even after taking family income into account, says Dr. Orjuela. “There is a possibility that these children were exposed to metal or some other toxin in the dirt, although confirming this hypothesis would be difficult, given the rarity of the disease.”

The finding on maternal education may offer a more fruitful intervention. “We may need to rethink the costs and benefits of screening programs and consider how to improve survival among children with less-educated parents,” says Dr. Orjuela.

“Although pathologic stage and tumor histology are important in the diagnosis and prognosis of retinoblastoma, social factors can help us gain new insights into how the disease progresses and, eventually, new ways to prevent and treat it,” says co-author Lourdes Cabrera-Muñoz, MD, Departamento de Patologìa, Hospital Infantil de Mèxico, Mexico City.

This work represents the latest finding from a longstanding multi-institutional collaboration involving co-authors Aurora Medina-Sansón and M. Veronica Ponce-Castañeda at the Hospital Infantil de México Federico Gomez, Mexico City; and Xinhua Liu at the Mailman School.

 

http://www.medicalnewstoday.com/releases/274226.php

Picture courtesy of wonderwoman.intoday.in