Chromosome 7p12.3 microduplication

Chromosome 7p12.3 microduplication detected in an infant.

The clinical consequences of a duplication in the 7p12 area are virtually unknown. The authors report on an 11-month old girl with an association of anal atresia, perineal hamartoma (which appeared as a polyp-like protrusion in the perineum) and facial dysmorphism. The patient showed developmental delay, she could not sit without support. A lumbar MRI revealed a cystic lesion at the filum terminale (at the level of L2 vertebra). A cytogenetic examination showed a 0.55 Mb duplication in 7p12.3 area. The duplication occurred de novo, karyotypes of both parents were normal. The duplicated segment included four morbid genes – TNS3, PKD1L1, HUSI and UPP1. The authors discuss a possible role of each of these genes in the origin of birth defects in the child, but currently none of these genes can be considered as casual for this association. Generally the combination of anal atresia, perineal hamartoma and cystic lesions in the filum terminal occur only extremely rarely. Not a single of these defects have been previously found in association with duplications of this chromosomal area.

Kocaaga A. et al. “Case report: a de-novo 7p12.3 microduplication detected in an infant with perineal hamartoma and imperforate anus”. “Egypt. J. Med. Hum. Genet” 2021, v. 22:88.

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