Question: What is (are) Stickler syndrome type 1 ?
Answer: Stickler syndrome is a group of hereditary connective tissue disorders characterized by distinctive facial features, eye abnormalities, hearing loss, and joint problems. The features vary widely among affected people. Stickler syndrome type 1 may be divided into 2 subgroups: the membranous vitreous type and a predominantly ocular type. Both are caused by mutations in the COL2A1 gene. Stickler syndrome type II, sometimes called the beaded vitreous type, is caused by mutations in the COL11A1 gene. Stickler syndrome type III, sometimes called the nonocular form, is caused by mutations in the COL11A2 gene. These forms of Stickler syndrome are inherited in an autosomal dominant manner. Stickler syndrome type IV is caused by mutations in the COL9A1 gene, and Stickler syndrome type V is caused by mutations in the COL9A2 gene. These types of Stickler syndrome are inherited in an autosomal recessive manner.
Source: GARD

Question: What are the symptoms of Stickler syndrome type 1 ?
Answer: What are the signs and symptoms of Stickler syndrome type 1? The Human Phenotype Ontology provides the following list of signs and symptoms for Stickler 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 vitreous humor 90% Cataract 90% Long philtrum 90% Myopia 90% Retinal detachment 90% Short nose 90% Skeletal dysplasia 90% Abnormality of the mitral valve 50% Abnormality of vertebral epiphysis morphology 50% Arthralgia 50% Cleft palate 50% Disproportionate tall stature 50% Joint hypermobility 50% Osteoarthritis 50% Platyspondyly 50% Proptosis 50% Sensorineural hearing impairment 50% Cognitive impairment 7.5% Conductive hearing impairment 7.5% Visual impairment 7.5% Anteverted nares - Arachnodactyly - Arthropathy - Autosomal dominant inheritance - Beaking of vertebral bodies - Blindness - Depressed nasal bridge - Flat midface - Glaucoma - Irregular femoral epiphysis - Kyphosis - Malar flattening - Mitral valve prolapse - Pectus excavatum - Pierre-Robin sequence - Scoliosis - Spondyloepiphyseal dysplasia - 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