Deletion 21pterq22.11: Report of a Patient with Dysmorphic Features, Hypertonia, and Café-au-Lait Macules and Review of the Literature.

Partial monosomy 21 results in a great variability of clinical features that may be associated with the size and location of the deletion. In this study, we report a 22-month-old girl who showed a 45, XX, add(12)(p13) dn,-21 karyotype. The final cytogenomic result was 45, XX, der(12) t(12; 21)(p13; q22.11) dn,-21. arr[hg19] 21q11.2q22.11(14824453_33868129) x1 revealing a deletion from 21pter to 21q22.11. Clinical manifestation of the patient included hypertonia, a long philtrum, epicanthic folds, low-set ears, and cafe-au-lait macules - a phenotype considered as mild despite the relatively large size of the deletion compared to patients from the literature. (c) 2017 S. Karger AG, Basel