The first Turkish case with early-juvenile-onset recessive distal titinopathy and the first case with prominent neurogenic involvement

Objectives Recessive titinopathies are an extremely rare spectrum of diseases in which muscle weakness accompanied by contractures.Patients present with hypotonia at birth,congenital myopathy characterized by delayed motor development within the first 12 months of life, or distal or proximal myopathy with onset in childhood or later. Methods Herein, we present the first case of juvenile-onset recessive titinopathy from Turkey. This case also the first case of recessive titinopathy with marked neurogenic involvement who presented with muscle twitches and spasms in literature. Results A 15-year-old boy presented with complaints of fatigue, weakness,twitching and cramps in the extremity muscles.It was learned from his medical history that he was investigated due to moderate creatine kinase elevation in an external center and chronic diffuse neurogenic changes were found in the electroneuromyographic examination.His muscle biopsy revealed chronic neurogenic atrophy.SMN1 and ALS2 gene analyzes were normal at external center.His family history was unremarkable except that the mother and father were cousins.In his neurological examination, weakness in the distal upper extremities,thenar-hypotenar atrophy and moderate weakness in the proximal lower extremities, fasciculation in the muscles, pes planus and positive Gowers' sign were revealed. Riboflavin was initiated for treatable neuronopathies. A new compound heterozygous p.I5079L (c.15235A>T) and p.G16602R (c.49804G>A) (NM133378.4) mutations in the TTN gene were detected in whole exome analysis. Conclusions Recessive titinopathies are myopathies with congenital and non-congenital onset, with distal or proximal involvement and accompanied by contractures. This case is the first case in which neurogenic findings are prominent which expands the clinical spectrum of titinopathy.
Keywords: Turkish, titinopathy ,juvenile-onset, myopathy, elevated CK , contracture