Black Hair Follicular Dysplasia is a condition where the black hair does not develop properly, is brittle and breaks off easily. The hair is also not black but slate grey. The Large Munsterlander pup at left, has normal hair in its white patches but abnormal hair is its grey/black patches. HealthGene Laboratory offers the DNA test for this autosomal recessive condition in some but not all breeds (i.e. the Large Munsterlander, Newfoundland, Great Dane, Doberman Pinscher). The eyes often remain blue instead of turning to brown. Occasionally, these dogs may also be deaf.

Color-dilution alopecia appears to be the same disorder as Black Hair Follicular Dysplasia but covers a wider range of coat colors. It is also called Blue Doberman Syndrome, Fawn Irish Setter Syndrome, and Blue Dog disease.

Some dogs who are born white are also deaf. These white dogs are usually those that are white from merle crosses or from crosses of "flashy" marked Boxers. Some Dalmatians are also unilaterlly or bilaterally deaf.

We recently studied a group of 26 deaf Australian Shepherds who were merle with a considerable amount of white using the mutation in the SILV gene reported recently (see merle page for more details). Twenty-four were homozygous for this mutation. Apparently in other breeds that are merle without other white markings, deafness is less likely (reported by Murphy et al. at the Canine & Feline Genetics meeting in Davis, CA August, 2007).

Recent DNA studies reveal that the white markings of Boxers and Dalmatians, as well as several other dogs such as Landseer Newfoundlands and Cavalier King Charles Spaniels which do not exhibit associated deafness, are caused by a mutation/s in the MITF gene. See another webpage in this series more information about white spotting.

C.C. Little believed that albinism was rare in dogs. If one defines albinism as the complete lack of pigment in eyes, nose, pads, skin and hair then it probably is quite rare. The lack of pigment in some or all of these parts is probably less rare.

The gene causing albinism in Doberman Pinchers was identified by Paige Winkler and colleagues in Michigan and is SLC45a2. Subsequently Hiruni Wijesenda identified a second mutation in this gene that caused albinism in several small long-haired breeds. However, neither mutation is present in the albino pug at the right, so there must be at least one other mutation in this gene or another gene causing albinism in dogs. See another webpage in this series more information about albinism.

Micropthalmia or "small eye" is a condition that occurs frequently in dogs homozygous for Merle. This condition also appears to be inherited in Akita, irrespective of their coat color. There is a gene known as MITF (microphthalmia transcription factor) that is very important in eye development and also coat color. Therefore we studied this gene extensively but thus far have failed to find a connection to either the microphthalmia of Akita.