2009 Vienna - European Society of Human Genetics

Evolutionary and population genetics, and Genetic epidemiology
P10.78
Retrospective epidemiological study of spinal muscular atrophy
in slovenia
N. Teran 1 , B. Gornjak-Pogorelc 2 , D. Neubauer 3 , J. Zidar 4 , B. Peterlin 1 ;
1 UMC Ljubljana, Dept. of Obst. and Gynecol., Institute of Medical Genetics, Ljubljana,
Slovenia, 2 University of Ljubljana, Medical Faculty, Institute of Forensic
Medicine, Ljubljana, Slovenia, 3 UMC Ljubljana, University Childrens’ Hospital,
Dept. of Pediatric Neurology, Ljubljana, Slovenia, 4 UMC Ljubljana, Div. of Neurology,
Institute of Clinical Neurophysiology, Ljubljana, Slovenia.
Introduction: Spinal muscular atrophy (SMA) is one of the most common
autosomal-recesive neuromuscular disorder. It has a prevalence
of between 1 in 6000 and 1 in 10,000 live births in Caucasian populations.
The epidemiology of SMA in our country was not published yet.
In retrospecitve study we examined patients with clinical diagnosis of
SMA in order to estimate the prevalence of SMA.
Material and Methods: Molecular genetic analysis was performed
for patients with a clinical diagnosis of SMA, whose blood samples
was sent to our laboratory during the 10 years period (from 1998 until
2008). PCR/RFLP analysis was used to detect homozygous deletion
of the SMN1. MLPA analysis was found to be an efficient method for
detecting copy numbers of SMN1 and SMN2.
Results: After screening by PCR/RFLP analysis 75 out of 158 patients
had homozygous SMN1 deletion. Exons 7 and 8 were homozygously
deleted in 58 patients (77%), while 17 (23%) showed deletion of only
exon 7. In one SMA patient, MLPA revealed 1 copy of SMN1. In one
family, 2 sibilings with SMA and 1 non-affected showed only homozygous
deletion of SMN2. Additionaly, homozygous deletion of SMN2
was detected in the mother, whereas her daughter’s lack both copies
of SMN1. The prevalence of SMA was estimated at 3.94/10 5 on September
30 st 2008 .
Conclusions: The prevalence is comparable to previously reported
data in other Caucasian populations. Due to complexity of SMA genetics,
testing of additional family members should be suggested and
offered when appropriate.
P10.79
Age- and sex- related reduction of relative telomere length over
ten years in the population-based Bruneck study: Application of
a high-throughput real-time PcR genotyping assay
A. Brandstätter1 , S. Ehrlenbach1 , P. Willeit2 , S. Kiechl2 , J. Willeit2 , F. Kronenberg1
;
1 2 Division of Genetic Epidemiology, Innsbruck, Austria, Department of Neurology,
Innsbruck, Austria.
Background: Telomeres play a key role in the maintenance of chromosome
integrity and stability. Telomere length is linked to age-related
diseases, with shorter telomeres associated with an increased probability
of mortality from infection or heart disease. Our aim was to determine
the decrease rate of telomere length over a time period of ten
years and whether this decrease rate was influenced by age, sex and
smoking behaviour.
Research design and methods: We compared relative telomere lengths
(RTL) in 510 sample pairs from the longitudinal population based Bruneck
study, which were collected in 1995 and ten years later in 2005.
RTL were determined by a high-throughput real-time genotyping assay
and by applying various mathematical models.
Results: Rate of change in RTL was highly variable among individuals.
Mean telomere length decreased over ten years by 20.4% (95% CI:
16.8 - 24.1; p