Guzmán-Santiago Tania Alejandra, Juárez-Melchor Daniela, Jiménez-Pérez Berenice, Vera-Loaiza Aurea, Pérez-Arzola Alan Alberto, Hernández-Castañeda Yazmin, Rodríguez-Hurtado Pablo Omar, Crisanto-López Israel Enrique, Garduño-Zarazúa Luz María, Salazar-Bonilla Wilbert
Instituto Mexicano del Seguro Social, Hospital General de Zona No. 20 "La Margarita", Servicio de Genética Médica. Puebla, Puebla, México.
Instituto Mexicano del Seguro Social, Centro Médico Nacional Siglo XXI, Hospital de Pediatría "Dr. Silvestre Frenk Freund", Laboratorio de Citogenética. Ciudad de México, México.
Rev Med Inst Mex Seguro Soc. 2025 Jan 3;63(1):e6352. doi: 10.5281/zenodo.13381482.
When a chromosome undergoes 2 distal breaks and the broken ends join together, they form a ring chromosome. Ring 21 syndrome is described with a phenotype with minor dysmorphisms, thrombocytopenia, psychomotor and language delay. The objective of this work is to display 2 cases of male patients with ring chromosome 21.
The first case was a 5-year-old male patient, with psychomotor and language delay. Broad forehead with prominent metopic suture, bilateral epicanthic fold, hypotelorism, left esotropia, low-set asymmetrical pinnae, micrognathia, lower extremities with deep plantar folds. Karyotype 46,XY,r(21)(p11.2q21)[25]. The second case was an 8-year-old male patient with psychomotor and language delay. Skull with flattened occiput, triangular facies, midfacial flattening, palpebral fissures directed downwards, bilateral epicanthic fold, low-set and asymmetrical pinnae, micrognathia, prominent asymmetrical thorax on the right side, hands with irregular palmar folds. Karyotype: 46,XY,r(21)(p11q22)[25].
Craniofacial dysmorphisms with psychomotor and language delay were the most relevant clinical data in both cases.
当一条染色体发生两次远端断裂且断裂末端连接在一起时，就会形成环状染色体。21号环状染色体综合征的特征表现为存在轻微畸形、血小板减少、精神运动和语言发育迟缓。本文旨在展示2例21号环状染色体男性患者的病例。
第一例为一名5岁男性患者，存在精神运动和语言发育迟缓。前额宽阔，额缝明显，双侧内眦赘皮，眼距过窄，左眼内斜视，耳廓低位且不对称，小颌畸形，下肢足底有深褶。核型为46,XY,r(21)(p11.2q21)[25]。第二例为一名8岁男性患者，有精神运动和语言发育迟缓。颅骨枕部扁平，面部呈三角形，面中部扁平，睑裂向下，双侧内眦赘皮，耳廓低位且不对称，小颌畸形，右侧胸廓突出且不对称，手部掌褶不规则。核型：46,XY,r(21)(p11q22)[25]。
颅面部畸形伴精神运动和语言发育迟缓是两例患者最相关的临床资料。
