Question: What is (are) Crigler Najjar syndrome, type 1 ?
Answer: Crigler Najjar syndrome, type 1 is an inherited disorder in which bilirubin, a substance made by the liver, cannot be broken down. This condition occurs when the enzyme that normally converts bilirubin into a form that can easily be removed from the body does not work correctly. Without this enzyme, bilirubin can build up in the body and lead to jaundice and damage to the brain, muscles, and nerves. Crigler Najjar syndrome, type 1 is caused by mutations in the UGT1A1 gene. The condition is inherited in an autosomal recessive manner. Treatment relies on regular phototherapy throughout life. Blood transfusions and calcium compounds have also been used. Liver transplantation may be considered in some individuals.
Source: GARD

Question: What are the symptoms of Crigler Najjar syndrome, type 1 ?
Answer: What are the signs and symptoms of Crigler Najjar syndrome, type 1? The Human Phenotype Ontology provides the following list of signs and symptoms for Crigler Najjar syndrome, type 1. 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) Abnormality of the liver 90% Hearing impairment 7.5% Memory impairment 7.5% Ophthalmoparesis 7.5% Seizures 7.5% Autosomal recessive inheritance - Encephalopathy - Jaundice - Kernicterus - Unconjugated hyperbilirubinemia - 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