Bacci Giacomo M, Donati Maria A, Pasquini Elisabetta, Munier Francis, Cavicchi Catia, Morrone Amelia, Sodi Andrea, Murro Vittoria, Garcia Segarra Nuria, Defilippi Claudio, Bussolin Leonardo, Caputo Roberto
Pediatric Ophthalmology Unit, Meyer Children's Hospital, University of Florence, Florence, Italy.
Metabolic Disease and Newborn Screening Clinical Unit, Neuroscience Department, Meyer Children's Hospital, Florence, Italy.
Acta Ophthalmol. 2017 Dec;95(8):e776-e782. doi: 10.1111/aos.13441. Epub 2017 May 8.
To describe the retinal structure of a group of patients affected by methylmalonic aciduria with homocystinuria cblC type, caused by mutations in the MMACHC gene, using spectral domain optical coherence tomography (SD-OCT).
Young patients (n = 11, age 0-74 months) with cblC disease, detected by newborn screening or clinically diagnosed within 40 days of life, underwent molecular analysis and complete ophthalmic examination, including fundus photography and SD-OCT. In one case, we also performed fluorescein angiography (FA) and standard electroretinography (ERG).
Molecular analysis of the MMACHC gene fully confirmed cblC disease in nine of 11 patients. Two patients harboured only a single heterozygous pathogenic MMACHC mutation and large unbalanced rearrangements were excluded by array-CGH analysis in both. All patients except two showed a bilateral maculopathy. In general, retinal changes were first observed before one year of age and progressed to a well-established maculopathy. Measurable visual acuities ranged from normal vision, in keeping with age, to bilateral, severe impairment of central vision. Nystagmus was present in six patients. Spectral domain optical coherence tomography (SD-OCT) showed macular thinning with severe alterations in outer, and partial sparing of inner, retinal layers.
Patients affected by cblC disease may frequently show an early onset maculopathy with variable ophthalmoscopic appearance. Spectral domain optical coherence tomography (SD-OCT) broadens the knowledge of subtle retinal alterations during the disease's progression and helps to shed light on the pathological mechanism of maculopathy development.
利用频域光学相干断层扫描（SD - OCT）描述一组因MMACHC基因突变导致的伴有高同型半胱氨酸尿症的甲基丙二酸尿症cblC型患者的视网膜结构。
通过新生儿筛查或在出生后40天内临床诊断出患有cblC疾病的年轻患者（n = 11，年龄0 - 74个月）接受分子分析和全面的眼科检查，包括眼底照相和SD - OCT。在1例患者中，我们还进行了荧光素血管造影（FA）和标准视网膜电图（ERG）检查。
MMACHC基因的分子分析在11例患者中的9例中完全证实了cblC疾病。2例患者仅携带单个杂合致病性MMACHC突变，且两者均通过阵列比较基因组杂交（array - CGH）分析排除了大片段不平衡重排。除2例患者外所有患者均表现为双侧黄斑病变。一般来说，视网膜改变在1岁前首次被观察到，并进展为明确的黄斑病变。可测量的视力范围从与年龄相符的正常视力到双侧严重的中心视力损害。6例患者存在眼球震颤。频域光学相干断层扫描（SD - OCT）显示黄斑变薄，外层视网膜有严重改变，内层视网膜部分保留。
患有cblC疾病的患者可能经常表现出早期黄斑病变，眼底镜表现各异。频域光学相干断层扫描（SD - OCT）拓宽了我们对疾病进展过程中细微视网膜改变的认识，并有助于阐明黄斑病变发生的病理机制。
