What are the signs and symptoms of Myotonic dystrophy? Signs and symptoms of myotonic dystrophy often begin in a person's 20s or 30s, but they can begin at any age. Symptoms often include progressive muscle weakness and wasting (particularly in the legs, hands, neck and face); stiffness and tightness of the muscles; cataracts; and cardiac conduction defects (irregular electrical control of the heartbeat). Some affected men also have hormonal changes that may cause balding or infertility. The severity of symptoms can vary widely among affected people. The signs and symptoms of type 1 and type 2 overlap, but type 2 is generally more mild than type 1. People who are born with the condition have congenital myotonic dystrophy, which is a variation of type 1. Congenital myotonic dystophy causes weakness of all muscles, in addition to breathing problems, developmental delays and intellectual disabilities. The Human Phenotype Ontology provides the following list of signs and symptoms for Myotonic dystrophy. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Arrhythmia 90% Cataract 90% EMG abnormality 90% Hypertonia 90% Mask-like facies 90% Myotonia 90% Skeletal muscle atrophy 90% Abnormality of the endocrine system 50% Cognitive impairment 50% Facial palsy 50% Muscular hypotonia 50% Respiratory insufficiency 50% Abnormal hair quantity 7.5% Abnormality of the hip bone 7.5% Abnormality of the upper urinary tract 7.5% Cryptorchidism 7.5% Hernia of the abdominal wall 7.5% Hydrocephalus 7.5% Non-midline cleft lip 7.5% Strabismus 7.5% Atrial flutter 4/11 Autosomal dominant inheritance - Cerebral atrophy - Cholelithiasis - Decreased fetal movement - Diabetes mellitus - Dysphagia - Elevated follicle stimulating hormone - Elevated serum creatine phosphokinase - Excessive daytime sleepiness - Facial diplegia - Feeding difficulties in infancy - First degree atrioventricular block - Frontal balding - Hypogonadism - IgG deficiency - IgM deficiency - Insulin insensitivity - Intellectual disability, progressive - Intellectual disability, severe - Iridescent posterior subcapsular cataract - Myalgia - Neck flexor weakness - Obsessive-compulsive trait - Oligospermia - Palpitations - Polyhydramnios - Proximal muscle weakness - Respiratory distress - Tachycardia - Testicular atrophy - Type 2 muscle fiber atrophy - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.