A new B.C. study compares children with Neuroﬁbromatosis 1 (NF1) to their healthy siblings to better understand the reasons why kids with NF1 have lower bone density.
About one in every 3,500 children is born with NF1. Symptoms include café-au-lait spots on the skin, short stature, and benign tumors that can cause pain, nerve damage and disfigurement.
Previous research has shown that people with NF1 also have bones that are less dense than unaffected people, however; scientists weren’t sure why. Bones that are less dense are more susceptible to breaks, bending and stress.
In a study published in the American Journal of Medical Genetics, researchers at the Child & Family Research Institute (CFRI) at BC Children’s Hospital compared 18 children in BC who have NF1 with their unaffected sibling.
“The sibling control study allows us to observe subtle but significant differences between the biology of people with NF1 and those without,” says Dr. Linlea Armstrong, the lead author on the study.
The study reveals that children with NF1 have higher calcium levels than their siblings and they also go through puberty later.
“These measures were within the ‘normal ranges’ for participants with NF1, but respectively higher and later than they were for their siblings,” says Dr. Armstrong. “We cannot overlook the potential cumulative effect of these subtle differences over a lifetime.”
Researchers will continue to study the mechanisms behind these differences. They’ll also investigate treatments like exercise and vitamin D supplementation that may improve bone health in children with NF1.
Dr. Armstrong is a Clinical Investigator at CFRI, a Medical Geneticist at BC Children’s and BC Women’s Hospital & Health Centre, and a Clinical Associate Professor with the UBC Department of Medical Genetics. Co-authors include Dr. Jan Friedman, Patricia Birch and Kimberly Jett. Dr. Friedman is a Senior Clinician Scientist at CFRI, Medical Geneticist at BC Children’s and BC Women’s, and a Professor with the UBC Department of Medical Genetics; Patricia is a Research Manager at CFRI; and Kimberly is a UBC Doctoral Student at CFRI.
Armstrong L, Jett K, Birch P, Kendler DL, McKay H, Tsang E, Stevenson DA, Hanley DA, Egeli D, Burrows M, Friedman JM. "The generalized bone phenotype in children with neurofibromatosis 1: a sibling matched case-control study." American Journal of Medical Genetics. 2013 Jul;161A(7):1654-61.