Question: What is (are) Paramyotonia congenita ?
Answer: Paramyotonia congenita is an inherited condition that affects muscles used for movement (skeletal muscles), mainly in the face, neck, arms, and hands. Symptoms begin in infancy or early childhood and include episodes of sustained muscle tensing (myotonia) that prevent muscles from relaxing normally and lead to muscle weakness. Symptoms in paramyotonia congenita worsen during exposure to cold temperatures, and unlike many other forms of myotonia, worsen with exercise and repeated movements. This condition is caused by mutations in the SCN4A gene and is inherited in an autosomal dominant pattern.
Source: GARD

Question: What are the symptoms of Paramyotonia congenita ?
Answer: What are the signs and symptoms of Paramyotonia congenita? The Human Phenotype Ontology provides the following list of signs and symptoms for Paramyotonia congenita. 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) Neonatal hypotonia 5% Autosomal dominant inheritance - Feeding difficulties - Handgrip myotonia - Infantile onset - Inspiratory stridor - Muscle stiffness - Muscle weakness - Myalgia - Paradoxical myotonia - Percussion myotonia - Phenotypic variability - Skeletal muscle hypertrophy - 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.
Source: GARD