Several cases of maternal UPD have been reported.
A phenotypically normal woman presented with repeated early miscarriages. The karyotype showed
iso(4p) and iso(4q) and biochemical "polymorphisms" suggested maternal disomy. The abstract
ambiguously states that polymorphic chromosome 4 marker studies indicated that she was possibly
isodisomic (Lindenbaum RH et al, Am J Med Genet. 1991; 49(Suppl): p.
Spena S et al (2004) described a case of
congenital afibrinogenaemia in a Thai proband due to maternal isodisomy. A 15-kb deletion was
discovered in the FGA
intron and FGA-FGB intergenic region. Imprinting was considered unlikely.
In a whole genome linkage study of psychiatric disorders in a Portuguese population a case of
maternal isodisomy was
identified in an adult female with a history of major depressive disorder (MDD). Apart from MDD the
phenotypically normal (Middleton FA et al 2006).
Losekoot M et al (2012) reported a
polycystic kidney disease, homozygous for a missense mutation in PKD2 due to segmental maternal
isodisomy at the
region of the PKD2 locus; the
chromosome 4 displayed maternal heterodisomy.
Cotrell CE et al (2012) described a male
with limb-girdle muscular dystrophy 2E (LGMD 2E) due to maternal UPD, leading to homozygosity for a
Papadimitriou DT et al (2015) reported a
old female patient with Wolfram Syndrome (WS) caused by maternal isodisomy that unmasked a
mutation in the WFS1 gene.
It is unlikely that there are any phenotypically significant maternally imprinted genes on
chromosome 4, as in all
cases reported so far, apart from the disease caused by homozygosity for specific mutations, the
A case of paternal UPD has been identified by Faas BH
et al (2010). The male proband had renal anomalies, a high forehead, small palpebral fissures,
“rough” hands and
feet with prominent distal phalanges, broad knees and normal psychomotor development.