Congenital myasthenic syndromes in Turkey: Clinical clues and prognosis with long term follow-up.

•We present clinical, electrophysiological and genetic findings of 69 patients from 51 families.•The most common CMS was primary acetylcholine receptor deficiency (31/51 families).•Fifteen families had COLQ, GFPT1, DOK7 deficiencies or slow channel CMS.•Distribution of muscle weakness and EMG were useful in giving a clue to the CMS subtype.•Due to the long follow-up, we were able to assess progression and to witness several pregnancies.