Dingo

11-20-2009, 01:20 PM

Risk of Spinal Deformity Among 1st Degree Relatives Of Children With Scoliosis

Author:

Dingo

Objective:

To estimate the risk of spinal deformity among 1st degree relatives of 41 Canadian children who underwent spinal fusion for Scoliosis.

Data:

The sample of 41 children comes from Dr. Moreau’s 2004 study, Melatonin Signaling Dysfunction in Adolescent Idiopathic Scoliosis. (Source (http://pico.sssup.it/files/allegati/2004_1469.pdf)) From the study, "Hereditary links were established by asking the patients and their relatives about the presence or not of a spinal deformity affecting a family member."

Family size comes from the 2006 Canadian census. (Source (http://www40.statcan.ca/l01/cst01/famil50a-eng.htm))

Background:

Scoliosis is the most common, childhood, spinal deformity. Spinal curves greater than 10 degrees occur in approximately 3 children in 100. Spinal curves greater than 20 degrees occur in approximately 1 child in 2000. (Source (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2674301/table/T1)) All children in this sample had severe Scoliosis and underwent spinal fusion. Cobb angles ranged from 30 degrees to 90 degrees. Curves of this magnitude occur in a small fraction of the patient population. It's possible that this sample contained children who posessed an increased, genetic susceptability to Scoliosis.

1st degree relatives share an average of 50% of the same genetic material. They include parents, siblings and fraternal twins. (Source (http://www.datadictionaryadmin.scot.nhs.uk/isddd/24260.html))

Results:

The risk of spinal deformity for parents was 7.3%

The risk of spinal deformity for siblings was 9.8%

The risk of spinal deformity for 1st degree females was 11.7%

The risk of spinal deformity for 1st degree males was 3.9%

Discussion:

The risk of spinal deformity among parents and siblings was similar. These numbers were consistent with earlier research which found that 1st degree relatives had an 11.1% risk of Scoliosis that was 20 degrees or greater. (Source (http://www.ejbjs.org/cgi/reprint/55/5/974.pdf)) 1st degree females had a 300% increased risk of spinal deformity compared to 1st degree males.

Calculations:

The sample included 41 children.

Out of 82 parents 6 had a spinal deformity. (6 / 82 = 7.3%)

Although it is likely that all siblings of patients who underwent spinal fusion would be screened for Scoliosis the same isn't true for parents. It is possible that this number understates the total number of parents with some type of deformity.

The number of siblings was not collected for Dr. Moreau’s study. Data from the 2006 Canadian census was used to determine the approximate number of siblings. According to the census among families who had children the average number of children living at home was 1.5. This suggests that 41 Canadian children would have approximately 20.5 siblings. In Dr. Moreau's sample 2 siblings had a spinal deformity. (2 / 20.5 = 9.8%)

1st degree females included 41 mothers and approximately 10.25 sisters (20.5 / 2) which amounted to 51.25 persons. Among this sample 6 had a spinal deformity (6 / 51.25 = 11.7%)

1st degree males included 41 fathers and approximately 10.25 brothers (20.5 / 2) which amounted to 51.25 persons. Among this sample 2 had a spinal deformity (2 / 51.25 = 3.9%)

Author:

Dingo

Objective:

To estimate the risk of spinal deformity among 1st degree relatives of 41 Canadian children who underwent spinal fusion for Scoliosis.

Data:

The sample of 41 children comes from Dr. Moreau’s 2004 study, Melatonin Signaling Dysfunction in Adolescent Idiopathic Scoliosis. (Source (http://pico.sssup.it/files/allegati/2004_1469.pdf)) From the study, "Hereditary links were established by asking the patients and their relatives about the presence or not of a spinal deformity affecting a family member."

Family size comes from the 2006 Canadian census. (Source (http://www40.statcan.ca/l01/cst01/famil50a-eng.htm))

Background:

Scoliosis is the most common, childhood, spinal deformity. Spinal curves greater than 10 degrees occur in approximately 3 children in 100. Spinal curves greater than 20 degrees occur in approximately 1 child in 2000. (Source (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2674301/table/T1)) All children in this sample had severe Scoliosis and underwent spinal fusion. Cobb angles ranged from 30 degrees to 90 degrees. Curves of this magnitude occur in a small fraction of the patient population. It's possible that this sample contained children who posessed an increased, genetic susceptability to Scoliosis.

1st degree relatives share an average of 50% of the same genetic material. They include parents, siblings and fraternal twins. (Source (http://www.datadictionaryadmin.scot.nhs.uk/isddd/24260.html))

Results:

The risk of spinal deformity for parents was 7.3%

The risk of spinal deformity for siblings was 9.8%

The risk of spinal deformity for 1st degree females was 11.7%

The risk of spinal deformity for 1st degree males was 3.9%

Discussion:

The risk of spinal deformity among parents and siblings was similar. These numbers were consistent with earlier research which found that 1st degree relatives had an 11.1% risk of Scoliosis that was 20 degrees or greater. (Source (http://www.ejbjs.org/cgi/reprint/55/5/974.pdf)) 1st degree females had a 300% increased risk of spinal deformity compared to 1st degree males.

Calculations:

The sample included 41 children.

Out of 82 parents 6 had a spinal deformity. (6 / 82 = 7.3%)

Although it is likely that all siblings of patients who underwent spinal fusion would be screened for Scoliosis the same isn't true for parents. It is possible that this number understates the total number of parents with some type of deformity.

The number of siblings was not collected for Dr. Moreau’s study. Data from the 2006 Canadian census was used to determine the approximate number of siblings. According to the census among families who had children the average number of children living at home was 1.5. This suggests that 41 Canadian children would have approximately 20.5 siblings. In Dr. Moreau's sample 2 siblings had a spinal deformity. (2 / 20.5 = 9.8%)

1st degree females included 41 mothers and approximately 10.25 sisters (20.5 / 2) which amounted to 51.25 persons. Among this sample 6 had a spinal deformity (6 / 51.25 = 11.7%)

1st degree males included 41 fathers and approximately 10.25 brothers (20.5 / 2) which amounted to 51.25 persons. Among this sample 2 had a spinal deformity (2 / 51.25 = 3.9%)