目的　探讨Pallister-Killian综合征（PKS）的细胞分子遗传学特点。方法 采集患儿外周血标本进行G显带染 色体核型分析，单核苷酸多态性-微阵列芯片（SNP array）技术鉴定异常片段来源，运用荧光原位杂交（FISH）技术加以确 认。结果 女性患儿，8月龄，因精神运动发育迟缓就诊。出生后有喂养困难、肌张力低下、面容异常、后发际线低、足部畸形、 双耳听力未过关等临床表现。外周血染色体G显带核型为mos 47，XX，+mar[18]/46，XX[82]；芯片分析结果发现患儿12 号染色体短臂嵌合重复，提示为12p四体嵌合体；FISH检测显示有48%的细胞有4个12p信号。结论 根据临床表现，常 规外周血染色体核型分析结合SNP-array及FISH检测诊断PKS。

Objective To explore the cytogenetic characteristics of Pallister-Killian syndrome (PKS). Methods Peripheral blood samples were collected for G-banding karyotype analysis. The source of abnormal fragments was identified by single nucleotide polymorphism-microarray (SNP array), and then confirmed by fluorescence in situ hybridization (FISH). Results An 8 -month-old girl visited the doctor for psychomotor retardation. She suffered from feeding difficulties, low muscle tension, abnormal facial appearance, low hairline, foot deformity, hearing loss and other clinical manifestations after birth. The G-banded karyotyping of peripheral blood chromosome showed mos 47, XX, +mar [ 18 ]/ 46, XX[ 82 ]. Affymetrix CytoScan 750K array analysis showed a mosaic duplication of the whole short arm of chromosome 12, indicating to be the 12p tetrasomy. FISH analysis confirmed that 48% of cells had four 12p signals. Conclusion? According to the clinical manifestations and routine peripheral blood karyotype analysis combined with SNP-array and FISH detection, PKS was diagnosed.