Cases of normal children with maternal UPD of chromosome 13 have been reported (Slater H et al 1994; Stallard R et al 1995).
Two unrelated Spanish patients with prelingual hearing impairment were identified with maternal UPD of chromosome
13 that unmasked a 35delG mutation in the GJB2 gene. GJB2 encodes connexin26, an important component of
intercellular gap junctions (Alvarez A et al 2003).
Yan D et al (2007) also report a case of hearing
loss due to a homozygous 35delG mutation in GJB2, however this time as a result of paternal UPD of chromosome 13.
Berend SA et al (1999) report two cases of normal
individuals with paternal UPD of chromosome 13.
Paternal UPD of chromosome 13 has been identified prenatally in children who have been born phenotypically normal
(Järvelä I et al 1998; Soler A et al 2000).
Paternal UPD of chromosome 13 in a patient revealed a mutation in the SACS gene, resulting in autosomal recessive
spastic ataxia of Charlevoix-Saguenay (ARSACS) (Anesi
L et al 2011).
There is no evidence to suggest that there are any phenotypically important imprinted genes on chromosome 13.