The first de novo non-mosaic 14q11.2q13.1 tetrasomy of paternal origin.

Tetrasomy 14q11q13 is a very rare chromosome aberration. So far, only five patients with such an imbalance were described. All these patients had a de novo marker chromosome idic(14)(q13) leading to a partial tetrasomy of chromosome 14. We report on the first case of a de novo non-mosaic partial tetrasomy 14q resulted not from a marker chromosome, but from an inverted triplication on paternal chromosome 14, characterized by using FISH and SNP array. Our patient showed some anomalies described in tetrasomy 14q11q13 with striking presence of paternal UPD(14) features (blepharophimosis, small thorax, and joint contractures, developmental delay). This unique patient supports the hypothesis that 14q11q13 may contain imprinted gene(s) that contribute to the paternal UPD(14) features of joint contractures and/or blepharophimosis. This patient demonstrates the utility of parent of origin testing in patients with de novo chromosome 14 aberrations. Overdosage of 14q11.1q13.1 may cause some features related to UPD(14) phenotype.

Deletion of 14.7 Mb 2q32.3q33.3 with a marfanoid phenotype and hypothyroidism.

Interstitial 2q deletions are very rare chromosome abnormalities. The 2q32q33 deletion was proposed as a distinct entity with characteristic phenotype. Most patients have feeding problems, growth restriction, moderate to severe developmental delay, speech delay or lack of speech, high, prominent forehead, thin sparse hair, teeth abnormalities and a high or cleft palate. We report on another rare case of interstitial 2q33 deletion found during routine karyotyping and further characterized by the use of a genomic SNP array. The patient presented here has a "Marfanoid" phenotype, hypothyroidism, and a marked tactile hypersensitivity. We concluded that hypothyroidism might be caused by the deletion of the CD28 and/or CTLA4 genes; also cardiological monitoring of patients with the deletion including BMPR2 may be considered in order to prevent the possible medical complications associated with pulmonary hypertension.