LAMA2-related muscular dystrophy (LAMA2-MD) is classified into congenital muscular dystrophy type 1A (MDC1A) and autosomal recessive limb-girdle muscular dystrophy-23 (LGMDR23). The purpose of this study was to identify the involvement pattern of thigh muscles of LAMA2-MD patients on magnetic resonance imaging. Fourteen MDC1A and 3 LGMDR23 patients were included, with 21 known and 8 novel LAMA2 disease-causing variants. In LAMA2-MD, the gluteus maximus, anterior (quadriceps femoris) and posterior (adductor magnus and biceps femoris) thigh muscles were extensively and severely affected with fatty infiltration, with relatively sparing of the adductor longus. The pattern of muscle involvement was similar between MDC1A and LGMDR23, but more severe in MDC1A, as well as in LAMA2-MD patients without ambulation. The rather peculiar pattern of the adductor magnus and long head of the biceps femoris first and severely affected in the mid-thigh level was found in LGMDR23. Strong correlation between fatty infiltration and age as well as disease duration was observed for the adductor longus in MDC1A. Edema and atrophy selectively involved in some muscles. The pattern of fatty infiltration on thigh muscle MRI of LAMA2-MD could provide important information for the diagnosis, differential diagnosis and assessment of clinical severity.

LAMA2相关性肌营养不良症（LAMA2-MD）分为先天性肌营养不良症1A型（MDC1A）和常染色体隐性遗传性肢带型肌营养不良症23（LGMDR23）。本研究的目的是在磁共振成像中确定LAMA2 -MD 患者大腿肌肉的受累模式。包括 14 名 MDC1A 和 3 名 LGMDR23 患者，其中 21 种已知和 8 种新的LAMA2致病变异。在LAMA2 中-MD，臀大肌、前部（股四头肌）和后部（内收肌和股二头肌）大腿肌肉受到脂肪浸润的广泛而严重的影响，而内收长肌相对较少。MDC1A 和 LGMDR23 的肌肉受累模式相似，但在 MDC1A 和没有行走的 LAMA2-MD 患者中更严重。在 LGMDR23 中发现了相当奇特的大内收肌和股二头肌长头首先在大腿中部受到严重影响。在 MDC1A 中观察到长内收肌的脂肪浸润与年龄以及疾病持续时间之间存在很强的相关性。水肿和萎缩选择性地涉及某些肌肉。LAMA2大腿肌肉MRI脂肪浸润模式-MD可以为临床严重程度的诊断、鉴别诊断和评估提供重要信息。