Mosaic monosomy 14: clinical features and recognizable facies

Abstract

A 1-year-old child with clinical features of monosomy 14 is reported. She has dysmorphic facial features including ocular colobomata, dolichocephaly and microcephaly, retinal pigmentation, severe seizures, fair curly hair and tapering fingers. There was severe mental retardation. This is the first reported case of severe mosaic monosomy 14, with up to 30% mosaicism. A recognizable facial gestalt is present in children with 14q deletions or partial monosomy 14, as well as susceptibility to infection, feeding difficulties, seizures and retinal pigmentation.

Should embryos with autosomal monosomy by preimplantation genetic testing for aneuploidy be transferred?: Implications for embryo selection from a systematic literature review of autosomal monosomy survivors

“…A single case report of monosomy 14 mosaicism has been reported in a 1‐year old girl. She had severe intellectual disability and seizures, with dysmorphic features including ocular colobomata and tapering fingers …”

Prenatal Diagnosis of a Fetus with Congenital Heart Defect and Ring Chromosome 14

“…As a result, the immunoglobulin heavy chain gene is disrupted and consequently presents haploinsufficiency in this gene. This may account for the recurrent respiratory infections observed in these patients [4]. Moreover, the formation of the ring chromosome alters the chromosomal structure modulating the expression of genes, which under normal conditions would be very distant.…”