Limb-Girdle Muscular Dystrophy Type 2I in Norway

Echo intensity of muscles

Change in echo intensity at a defined cross-sectional level in muscles in limbs, musculus rectus abdominis and paraspinal muscles from baseline at 2 years. Echo intensity is measured as grayscale pixels ranging from 0 (black) to 255 (white) through histogram analysis by an ultrasound software program. It calculates the mean value from the superficial 1/3 of a manually selected region of interest in three consecutive images from same location. Increase in echo intensity indicates increase in pathology.

Time frame: Baseline and 2 years

Muscle thickness

Using ultrasound to measure changes in muscle thickness at a defined cross-sectional level in muscles in limbs, musculus rectus abdominis and paraspinal muscles from baseline at 2 years.

Time frame: Baseline and 2 years

Age at important disease stages

Document the variation in age of onset, age of loss of walking ability, age of established cardiac failure and age of established respiratory failure.

Time frame: Retrospective data collection at baseline

Rate of symptom progression

Document the variation in time from disease onset to loss of walking ability

Time frame: Retrospective data collection at baseline

Prevalence of recognized cardiomyopathy

The percentage of females and males with recognized cardiomyopathy

Time frame: Retrospective data collection at baseline

Prevalence of initiated ventilation support

The percentage of female and males that have initiated ventilation support.

Time frame: Retrospective data collection at baseline

Motor task performance

Using the standardised scoring instrument "Motor Function Measure for neuromuscular diseases" (MFM) to measure the ability to perform 32 different motor tasks. The individual item score ranges from 0 (cannot initiate the task) to 3 (performs fully and normally). The items are divided into 3 domains: 1) Standing and transfers (13 tasks), 2) Axial and proximal motor function (12 tasks), 3) Distal motor function (7 tasks). The 3 domains give rise to 3 subscores. Both subscores and total score (0-96 points) will be measured. Baseline and changes from baseline at two years.

Time frame: Baseline and 2 years

Disease-specific health-related quality of life (HRQOL)

Using the "Individualized Neuromuscular Quality of Life" (INQOL)-questionnaire to measure the burden of disease. It consists of 45 items. Each item is graded by a 7-point Likert scale (0-6/1-7).The 45 items make up 3 dimensions/domains: muscular symptoms, effects on life-domains (activities, independence, emotions, body image, social relationships) and effects of treatment. The 3 domains are together subdivided into 11 subdimensions, each with its own subscale. In addition there is a QOL-score which is a composite score from the "Life-domain". The scores range from 0-100 and are determined by the item responses and a weighting algorithm. The higher the scores, the more negative impact. Both subscales and QOL-score will be determined - at baseline and changes from baseline at 6 months, 1 year and 2 years.

Time frame: Baseline, at 6 months, 1 year

Echocardiography strain speckle-tracking

Measure cardiac function at baseline and changes from baseline at 2 years

Time frame: Baseline and 2 years

Nocturnal arterial carbon dioxide (CO2)-level

Monitor transcutaneous CO2 during sleep at baseline.

Time frame: Baseline

MRI

Muscle MRI lower limbs

Time frame: At 2 years