Chabrol B, Martens K, Meulemans S, Cano A, Jaeken J, Matthijs G, Creemers J W M
Reference Center for inborn metabolic disorders, CHU de la Timone, Marseille, France.
BMJ Case Rep. 2009;2009. doi: 10.1136/bcr.08.2008.0719. Epub 2009 Feb 2.
Hypotonia-cystinuria syndrome (HCS) and 2p21 deletion syndrome are two recessive contiguous gene deletion syndromes associated with cystinuria type I. In HCS patients, only SLC3A1 and PREPL are disrupted. In the 2p21 deletion syndrome, two additional genes (C2orf34 and PPM1B) are lost. Molecular analysis of the SLC3A1/PREPL locus was performed in the patients using quantitative polymerase chain reaction (PCR) methods. HCS in both siblings was confirmed with the deletion screen of the SLC3A1/PREPL locus. Fine mapping of the breakpoint revealed a deletion of 77.4 kb, including three genes: SLC3A1, PREPL and C2orf34. Features not present in classical HCS were a mild/moderate mental retardation and a respiratory chain complex IV deficiency. We report the first patients with a deletion of SLC3A1, PREPL and C2orf34. They present with a phenotype intermediate between HCS and 2p21 deletion syndrome.
肌张力减退 - 胱氨酸尿症综合征（HCS）和2p21缺失综合征是与I型胱氨酸尿症相关的两种隐性相邻基因缺失综合征。在HCS患者中，只有溶质载体家族3成员A1（SLC3A1）和脯氨酸内肽酶样蛋白（PREPL）被破坏。在2p21缺失综合征中，另外两个基因（C2orf34和丝氨酸/苏氨酸蛋白磷酸酶1B（PPM1B））缺失。使用定量聚合酶链反应（PCR）方法对患者的SLC3A1/PREPL基因座进行了分子分析。通过SLC3A1/PREPL基因座的缺失筛查确诊了这对兄弟姐妹均患有HCS。断点的精细定位显示缺失了77.4 kb，包括三个基因：SLC3A1、PREPL和C2orf34。经典HCS中不存在的特征是轻度/中度智力障碍和呼吸链复合物IV缺乏。我们报告了首例SLC3A1、PREPL和C2orf34缺失的患者。他们表现出的表型介于HCS和2p21缺失综合征之间。
