Supplementary Material for: Nonmosaic Trisomy 19p13.3p13.2 Resulting from a Rare Unbalanced t(Y;19)(q12;p13.2) Translocation in a Patient with Pachygyria and Polymicrogyria

Nonmosaic trisomy involving 19p13.3p13.2 is a very uncommon abnormality. At present, only 12 cases with this genetic condition have been reported in the literature. However, the size of the trisomic fragment is heterogeneous and thus, the clinical spectrum is variable. Herein, we report the clinical and cytogenetic characterization of a 5-year-old boy with nonmosaic trisomy 19p13.3p13.2 (7.38 Mb), generated by a derivative Y chromosome resulting from a de novo unbalanced translocation t(Y;19)(q12;p13.2). We demonstrated the integrity of the euchromatic regions in the abnormal Y chromosome to confirm the pure trisomy 19p. Our patient shares some clinical features described in other reported patients with pure trisomy 19p, such as craniofacial anomalies, developmental delay, and heart defects. Different to previous reports, our case exhibits frontal pachygyria and polymicrogyria. These additional features contribute to further delineate the clinical spectrum of trisomy 19p13.3p13.2.

累及19p13.3-p13.2区域的非嵌合型三体（nonmosaic trisomy）是一种极为罕见的染色体异常。目前，全球仅在医学文献中报道过12例此类遗传学异常病例。不过，该三体片段的长度存在异质性，因此对应的临床表型谱也各不相同。本文报告1例携带片段长度7.38 Mb的19p13.3-p13.2非嵌合型三体的5岁男性患儿的临床及细胞遗传学特征（cytogenetic characterization），该三体由新发不平衡易位（de novo unbalanced translocation）t(Y;19)(q12;p13.2)形成的衍生Y染色体（derivative Y chromosome）所导致。我们通过验证该异常Y染色体上常染色质区域的完整性，确认该患儿为纯合19p三体（pure trisomy 19p）。该患儿与此前报道的纯合19p三体患者存在部分共有临床特征，包括颅面畸形、发育迟缓及心脏缺陷。与既往报道不同的是，本病例同时出现了额叶厚脑回（frontal pachygyria）与多小脑回畸形（polymicrogyria）。这些新增的临床特征有助于进一步阐明19p13.3-p13.2三体的临床表型谱。