12q21.2q22 deletion: a new patient.

Interstitial deletions of long arm of chromosome 12 are rare, and the interstitial deletion 12q21.1q22 has been reported to the best of our knowledge in only four patients. Comparing the patients reported, a characteristic phenotypic pattern (facial features like prominent forehead, short and upturned nose, low set ears, and ectodermal abnormalities) can be identified. It has been suggested to be considered a deletion syndrome [Klein et al., (2005); Am J Med Genet 138:349-354]. We report on a 34-month-old girl, who was referred to our clinic at 6 months of age, presenting at birth with axial hypotonia, enlarged anterior fontanel, ventriculomegaly, dysmorphic facies (prominent forehead, sparse hair and eyebrows, short palpebral fissures), failure to thrive and development delay. Her cytogenetic study showed an interstitial deletion of the long arm of chromosome 12: 46,XX,del(12)(q21.1q22) redefined by array comparative genomic hybridization. We compare and review our patient with the four previously reported cases, plus one with a deletion with an overlap of the chromosomal region and phenotypic similarities. As far as we know our patient is the fourth reported with this cytogenetic abnormality. This additional report allows us to support a genotype-phenotype correlation for this chromosomal abnormality.