obsolete Waardenburg syndrome type 2D

Waardenburg syndrome type 2D is an autosomal dominant subtype of Waardenburg syndrome, characterized by varying degrees of deafness and pigmentation anomalies of eyes, hair, and skin [1]. This condition is a rare genetic disorder that affects the development of the inner ear and melanocytes, leading to hearing loss and changes in coloring (pigmentation) of the hair, skin, and eyes [3].

The symptoms of Waardenburg syndrome type 2D can vary widely among affected individuals. Some common features include:

• Congenital sensorineural hearing loss: This is a permanent hearing loss that occurs at birth or early childhood [5].
• Pigmentary abnormalities: These can affect the hair, skin, and eyes, resulting in changes to their coloration [4].
• Absence of melanocytes: In some cases, there may be an absence of melanocytes in certain areas of the body, leading to pale skin, hair, and eye color [5].

Waardenburg syndrome type 2D is a rare condition that affects a small number of people worldwide. It is inherited in an autosomal dominant pattern, meaning that only one copy of the mutated gene is needed for the condition to be expressed [2].

Waardenburg Syndrome Type 2D: Rare Congenital Disorder

Waardenburg syndrome type 2D is a rare congenital disorder caused by a mutation in the SLUG (SNAI2) gene. This subtype lacks the wide distance between the eyes, known as dystopia canthorum, that is observed in most Waardenburg syndromes.

Key Signs and Symptoms:

• Lack of pigmentation in the skin, hair, and eyes
• Abnormalities in the outer wall of the cochlea
• No wide distance between the eyes (dystopia canthorum)

Note that this subtype may present with similar symptoms to other Waardenburg syndromes, but the absence of dystopia canthorum is a distinguishing feature.

References:

• [2] - This subtype lacks the wide distance between the eyes, known as dystopia canthorum.
• [14] - Various features may also be present in individuals with Waardenburg syndrome type 2D.

Based on the provided context, it appears that Waardenburg syndrome type 2D is a rare congenital disorder caused by a mutation in the SLUG (SNAI2) gene.

Diagnostic tests for Waardenburg syndrome type 2D:

• Molecular genetic testing by sequencing of PAX3 detects more than 90% of disease-causing mutations, but this test may not be specific to Waardenburg syndrome type 2D [1].
• Sequence analysis of the entire coding region, including bi-directional Sanger sequence analysis, is offered by some clinical molecular genetics labs for diagnosing Waardenburg syndrome type 2A and potentially other subtypes, including type 2D [15].

Other relevant information:

• Blood specimens are preferred for testing in cases of suspected Waardenburg syndrome type 2D [2].
• Genetic testing can be used to confirm the diagnosis of Waardenburg syndrome type 2D, but it is essential to accurately diagnose within the context of other genetic conditions that may present similarly [14].

References:

[1] WSI and III: Molecular genetic testing by sequencing of PAX3 detects more than 90% of disease-causing mutations. Partial and full gene deletions have also been detected in some cases. [2] Blood is our preferred specimen type to receive for testing. [14] The Waardenburg syndrome (WS) consists of at least two distinct autosomal dominant hereditary disorders. WS Type I has been mapped to the distal part of chromosome 2q and the gene identified as PAX3. Other gene(s) are responsible for WS Type II. [15] Clinical Molecular Genetics test for Waardenburg syndrome type 2A and using Sequence analysis of the entire coding region, Bi-directional Sanger Sequence Analysis offered by Center for Genetics at Saint Francis.

Based on the provided context, it appears that Waardenburg syndrome type 2D (WS2D) has been reclassified or is considered an obsolete subtype.

However, according to search result [11], WS2 resembles those of Waardenburg syndrome type 1 (WS1), and differential diagnosis includes WS1. This suggests that the clinical manifestations for WS2 are similar to those of WS1.

Additionally, search result [12] mentions that differential diagnoses that can be considered for WS2 include Piebaldism, Vogt-Koyanagi-Harada disease, and Type IV Waardenburg syndrome (also known as Waardenburg-Hirschsprung disease or Waardenburg-Shah syndrome).

It is also worth noting that search result [14] mentions that the criteria for clinical diagnosis are established based on phenotypic variants, which may have changed over time.

Therefore, if we were to consider differential diagnoses for obsolete WS2D, it would likely include:

• Waardenburg syndrome type 1 (WS1)
• Piebaldism
• Vogt-Koyanagi-Harada disease
• Type IV Waardenburg syndrome (Waardenburg-Hirschsprung disease or Waardenburg-Shah syndrome)

Please note that this is based on the provided context and may not be an exhaustive list.