Ear Pits, Posterior Helical

Clinical Features

Best (1991) reported a large family with apparently autosomal dominant inheritance of pits in the posterior aspect of the helices of the ears. In addition, at least 2 cases of the Beckwith-Wiedemann syndrome (BWS; 130650) had occurred in this family. Best (1991) concluded that while PHEP can occur in 'normal' persons, it must be relatively rare and is frequently associated with BWS. He pointed out that the shape of the pits suggest that they may be caused by the infarction or degeneration of a small area of epithelium with subsequent healing leaving a defect. Study of linkage to DNA markers in the 11p15.5 region might help clarify the relationship to BWS. Aughton and Aughton (1992) pointed out that PHEP may be an isolated familial (probably dominant) trait with no relationship to BWS. Aughton and Aughton (1992), father and daughter, showed this phenomenon with no history of BWS in the family. Curry and Arabian (1989) observed minor anomalies of the posterior aspect of the pinnae in 4 parent/child pairs, including 1 pair with PHEP.

Posterior Earlobe Indentations

Fischlowitz et al. (2009) described a 3-generation family in which the proband, her mother and a maternal aunt, and her maternal grandmother all had bilateral indentations located on the posterior aspect of the ear lobe. The indentations were either round or elongated, and the surrounding area was unmarked. The skin appeared normal, showing no signs of deformation. The proband's mother had Hermansky-Pudlak syndrome (see 203300); the authors noted that ear malformations are not known to be associated with that condition. The 3 other affected individuals had no other abnormalities or hearing loss. Fischlowitz et al. (2009) stated that this was the first paper to report familial or isolated posterior earlobe indentations.

Mapping

Barr et al. (2001) examined 5 families with PHEP, 2 segregating with BWS and 3 with PHEP alone. The results indicated that the PHEP phenotype was not linked to chromosome 11p15.5 in 2 informative families tested. A third family was unlikely to be linked to this region, and data from 2 other families were inconclusive. In the families described, there was insufficient information to determine if BWS was linked to 11p15.5. The authors postulated that a second WBS locus may exist and that the PHEP phenotype is linked to this locus, or, alternatively, that the PHEP phenotype occurs independently of BWS.

Molecular Genetics

Guala et al. (2007) reported a mother and son with isolated ear pits and no other signs of BWS. The Italian father had no PHEP and a negative family history; the mother was adopted from Ecuador, thus no family information was available. No mutations were found in the exons, splice junctions, or promoter region of CDKN1C in either patient, and there was no microdeletion or methylation abnormality in imprinting centers 1 or 2; 11p15 duplication and uniparental disomy were also excluded. The authors stated that their findings supported the hypothesis that PHEP are genetically heterogeneous and could be inherited through different autosomal dominant mutations linked or independent from the BWS locus.