Objective: To analyze the clinical characteristics of patients with Mucopolysaccharidosis ⅣA (MPS ⅣA). Methods: A retrospective study was conducted on 111 patients with MPS ⅣA in Xinhua Hospital of Shanghai Jiao Tong University School of Medcine from December 2008 to August 2020, confirmed by enzyme activity and genetic testing. General situation, clinical manifestations and enzyme activity test results were analyzed. According to the clinical manifestations, it can be divided into severe, intermediate and mild group. The independent sample t test was used to compare the birth body length and weight of children with that of normal boys and girls, and group comparisons of enzyme activities were evaluated by median test. Results: One hundred and eleven unrelated patients, 69 males and 42 females, were classified into 3 subtypes: severe (n=85), intermediate (n=14), and mild (n=12). The age at symptom onset were 1.6 (1.0, 3.0) years, and at diagnosis were 4.3 (2.8, 7.8) years. Skeletal manifestations were observed in all patients and consisted mainly of pectus carinatum (96/111, 86.5%), motor dysfunction (78/111, 70.3%), spinal deformity (71/111, 64.0%), growth retardation (64/111, 57.7%), joint laxity (63/111, 56.8%) and genu valgum (62/111, 55.9%). Eighty-eight patients (88/111, 79.3%) with MPS ⅣA were also along with non-skeletal manifestations, mainly including snoring (38/111, 34.2%), coarse faces (34/111, 30.6%), and visual impairment (26/111, 23.4%). The most common skeletal manifestation was pectus carinatum (79 cases), and non-skeletal manifestation was snoring (30 cases) and coarse faces (30 cases) in severe patients, pectus carinatum (13 cases) and snoring (5 cases) in intermediate type, motor dysfunction (11 cases) and snoring (3 cases) and visual impairment (3 cases) in mild patients. The height and weight of severe patients began to fall below -2 s at 2-<5 years and 5-<7 years, respectively. At the age of 10-<15 years, the standard deviation score of the height of severe patients reached (-6.2±1.6) s in males and (-6.4±1.2) s in females, and the score of weight got (-3.0±1.1) s in males and (-3.5±0.5) s in females. The height of intermediate patients began to fall below -2 s at the age of 7-<10 years, and the standard deviation score of height were -4.6 s and -3.6 s in 2 males, and -4.6 s and -3.8 s in 2 females at the age of 10-<15 years. The weight remained within -2 s in 72.0% (18/25) of intermediate patients compared to age-matched healthy children. In the mild patients with MPS ⅣA, the mean standard deviation score of height and weight was within -2 s. The enzyme activities of mild patients (2.02 (1.05, 8.20) nmol/(17 h·mg)) were both significantly higher than that of intermediate (0.57 (0.47, 0.94) nmol/(17 h·mg)) and severe (0.22 (0, 0.59) nmol/(17 h·mg)) patients (Z=9.91, 13.98, P=0.005, 0.001), and the enzyme activity of intermediate patients was significantly higher than that of severe patients (Z=8.56, P=0.010). Conclusions: The clinical manifestations of MPS ⅣA are charactered by pectus carinatum, motor function impairment, spinal deformity and growth retardation. The clinical characteristics, growth rate and enzyme activity differ among the 3 subtypes of MPS ⅣA.
目的： 分析黏多糖贮积症（MPS）ⅣA型患儿的临床特点。 方法： 回顾性分析上海交通大学医学院附属新华医院2008年12月至2020年8月经酶活性和基因检测诊断为MPS ⅣA型的111例患儿的一般情况、临床表现及酶活性检测结果，根据临床表现分为重型、中间型和轻型，采用独立样本t检验比较患儿出生身长体重与正常男女童均值，采用中位数检验对酶活性的检测结果进行组间比较。 结果： 111例MPS ⅣA型患儿中男69例、女42例，重型85例、中间型14例、轻型12例。发现患儿异常的年龄1.6（1.0，3.0）岁，确诊年龄4.3（2.8，7.8）岁。所有患儿均出现骨骼病变表现，主要包括鸡胸96例（86.5%），运动功能受损78例（70.3%），脊柱异常71例（64.0%），生长速度缓慢64例（57.7%），关节松弛63例（56.8%），X型腿62例（55.9%）；88例（79.3%）患儿伴骨骼外表现，主要包括打鼾38例（34.2%），面容粗糙34例（30.6%），视觉损伤26例（23.4%）。鸡胸是重型（79例）和中间型（13例）中最常见的骨病表现，轻型中最常见的骨病表现为运动功能受损（11例）；重型中常见的骨骼外表现为打鼾（30例）及面容粗糙（30例），中间型中最常见的骨骼外表现为打鼾（5例），轻型中常见的骨骼外表现为打鼾（3例）和视觉损伤（3例）。重型患儿的身高及体重分别在2~<5岁和5~<7岁时逐渐开始低于正常儿童的-2 s，10~<15岁重型男、女患儿身高标准差分别为正常儿童的（-6.2±1.6）s和（-6.4±1.2）s，体重标准差分别达到（-3.0±1.1）s和（-3.5±0.5）s。中间型患儿7~<10岁时身高逐渐开始低于正常儿童的-2 s，10~<15岁2例中间型男性患儿身高分别为正常男童的-4.6 s和-3.6 s，2例中间型女性患儿身高分别为正常女童的-4.6 s和-3.8 s；72.0%（18/25）的中间型患儿体重在正常儿童-2 s内。轻型男女患儿各年龄段的身高及体重均在正常男女童的-2 s内。轻型患儿酶活性比中间型和重型均高［2.02（1.05，8.20）比0.57（0.47，0.94）和0.22（0，0.59）nmol/（17 h·mg），Z=9.91、13.98，P=0.005、0.001］，中间型比重型高（Z=8.56，P=0.010）。 结论： MPS ⅣA型患儿的临床表现主要为鸡胸、运动功能受损、脊柱异常及生长速度缓慢，不同型别的MPS ⅣA型患儿的临床表现、生长速度及酶活性不同。.