Question: What is (are) Waardenburg syndrome type 2 ?
Answer: Waardenburg syndrome type 2 is an inherited condition that can cause hearing loss and changes in coloring (pigmentation) of the hair, skin, and eyes. About 50 percent of those with Waardenburg syndrome type 2 have a hearing impairment or are deaf. Type 2 is one the most common forms of Waardenburg syndrome, along with type 1. Waardenburg syndrome type 2 may be caused by mutations in the MITF and SNAI2 genes. This condition is usually inherited in an autosomal dominant fashion, but can sometimes be inherited as an autosomal recessive trait.
Source: GARD

Question: What are the symptoms of Waardenburg syndrome type 2 ?
Answer: What are the signs and symptoms of Waardenburg syndrome type 2? In general, Waardenburg syndrome is characterized by varying degrees of hearing loss and changes in skin and hair color (pigmentation). Those with Waardenburg syndrome type 2, do not have a wide space between the inner corners of their eyes or other facial abnormalities. Most have a hearing impairment or are deaf and also have heterochromia of the iris (two different colored eyes). Other features of Waardenburg syndrome, including white forelock, premature graying of the hair, and irregular depigmentation of the skin, are less common in this type. The Human Phenotype Ontology provides the following list of signs and symptoms for Waardenburg syndrome type 2. 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) Heterochromia iridis 90% Premature graying of hair 90% Sensorineural hearing impairment 90% Hypopigmented skin patches 50% White forelock 50% Abnormality of the kidney 7.5% Abnormality of the pulmonary artery 7.5% Aganglionic megacolon 7.5% Ptosis 7.5% Telecanthus 7.5% Albinism - Autosomal dominant inheritance - Congenital sensorineural hearing impairment - Heterogeneous - Hypoplastic iris stroma - Partial albinism - Synophrys - Underdeveloped nasal alae - Variable expressivity - White eyebrow - White eyelashes - Wide nasal bridge - 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

Question: How to diagnose Waardenburg syndrome type 2 ?
Answer: How is a subtype of Waardenburg syndrome type 2 diagnosed? Subtypes of Waardenburg syndrome type 2 are determined by the suspected genetic cause of the condition in a family. In some subtypes, the genetic cause is a known gene. In other subtypes, the general location (locus) of the genetic cause has been identified, but the specific gene is not yet known. There are five different subtypes: Type 2A is caused by a change (mutation) in the MITF gene on chromosome 3 Type 2B is associated with a locus on chromosome 1 Type 2C is associated with a locus on chromosome 8 Type 2D is caused by mutations is the SNAI2 gene on chromosome 8 Type 2E is caused by mutations in the SOX10 gene on chromosome 22 Because subtypes are defined by the underlying genetic cause, they are not diagnosed by physical features identified during a physical exam. Physical features may be used to distinguish between types of Waardenburg syndrome, such as Type 1 or Type 2, but do not help identify a specific subtype.
Source: GARD