Scientists have solved the long-standing mystery of the only known albino gorilla in the world, claiming that its unusual white colouring was the result of inbreeding.
Snowflake was a male Western lowland gorilla. He was born in the wild and captured in 1966 by villagers in Equatorial Guinea. As the only known white gorilla in the world, Snowflake was a zoo celebrity until his death of skin cancer in 2003.
Now, Spanish researchers have sequenced the gorilla's entire genome, revealing that Snowflake was probably the offspring of a pairing between an uncle and a niece.
In humans, four genetic mutations are known to cause albinism, a syndrome marked by a lack of skin, eye and hair pigment. People with albinism are at high risk for vision problems and skin cancers because of this missing pigment.
Using frozen blood from Snowflake, researchers led by Tomas Marques-Bonet of the Institut de Biologia Evolutiva at the University of Pompeu Fabra sequenced the entire genome of the late ape.
Comparing that sequence with those of humans and nonalbino gorillas, Marques-Bonet and his colleagues narrowed down the cause of Snowflake's albinism to a single gene, known as SLC45A2.
Snowflake inherited a mutant form of this gene from both of his parents.
The gene has previously been linked to albinism in mice, horses, chickens and a species of fish, LiveScience reported.
The researchers combed through Snowflake's genome looking for stretches of DNA that were identical due to inbreeding.
They found that 12 per cent of the genes from Snowflake's mother and father matched, a number that points to an uncle and niece mating as the most likely parentage for Snowflake.
No one else has reported inbreeding in Western lowland gorillas, Marques-Bonet told the website, though some other gorilla subspecies with small populations have been known to turn to family to mate.
The findings were published in the journal BMC Genomics.