ABSTRACT
This study aimed to: classify a cohort of children and adolescents with myotonic dystrophy (dystrophia myotonica: DM) into congenital and childhood onset forms; estimate CTG expansion size; and quantify muscle strength, contractures, and motor function in children with DM and compare results with those of controls. Participants were clinically examined, medical records were reviewed, and isometric muscle strength, contractures, and motor function were measured. Participants were: 42 children with DM (18 females, 24 males; mean age 8y 9mo [SD 4y 7mo], range 10mo to 17y) and 42 age- and sex-matched, healthy controls. Children with DM were divided into three groups: severe congenital (n=13), mild congenital (n=15), and childhood (n=14). Children with childhood DM were significantly weaker than controls (wrist and ankle dorsiflexors [p=0.0044, p=0.0044 respectively]; hip abductors and flexors [p=0.0464, p=0.0217]; and knee flexors and extensors: [p=0.0382, p=0.0033]). Children with mild congenital DM were significantly weaker than controls in all assessed muscle groups. Contractures and skeletal deformities were more frequent at time of investigation than at birth, suggesting that foot and spine deformities in particular increase over time. Motor function score was significantly lower for children with DM than for controls. Children with severe congenital DM had the lowest motor function, with correlation between motor function and size of CTG repeat (p=-0.743). Children found jumping, heel standing, and head lifting the most difficult items to perform but few had difficulty walking, running, or stair climbing. DM in children is a heterogeneous disorder with a wide spectrum of muscle involvement, and owing to increased risk of contractures and skeletal deformities, regular follow-ups are recommended.
Subject(s)
Muscle, Skeletal/physiopathology , Myotonic Dystrophy/genetics , Trinucleotide Repeat Expansion/genetics , Adolescent , Case-Control Studies , Child , Child, Preschool , DNA/isolation & purification , Female , Humans , Infant , Isometric Contraction/physiology , Male , Motor Activity/physiology , Myotonic Dystrophy/classification , Myotonic Dystrophy/physiopathology , Severity of Illness Index , Walking/physiologyABSTRACT
Although most patients with cystic fibrosis (CF) are diagnosed in early childhood, the diagnosis may be delayed for patients with mild symptoms or single-organ disease. We describe a man with known infertility and a history of productive cough diagnosed with CF at 61 years of age. The patient carries two mutations and one variant in the CF transmembrane conductance regulator gene: 394delTT, P99L and R75Q. During a 15-year follow-up time he has developed significant pulmonary disease.
