BACKGROUND Microcephalic osteodysplastic primordial dwarfism type I (MOPD I, also known as Taybi-Linder syndrome) is a rare genetic disorder associated with severe intrauterine growth retardation, short stature, microcephaly, brain anomalies, stunted limbs, and early mortality. RNU4ATAC, the gene responsible for this disorder, does not encode a protein but instead the U4atac small nuclear RNA (snRNA), a crucial component of the minor spliceosome. Roifman syndrome is an allelic disorder of MOPD I that is characterized by immunodeficiency complications. CASE REPORT The patient described herein is an 18-year-old woman exhibiting congenital dwarfism and microcephaly with structural brain anomaly. She suffered human herpesvirus 6 (HHV-6)-associated acute necrotizing encephalopathy at the age of one, thereafter resulting in severe psychomotor disabilities. Genetic analysis using gene microarray and whole-exome sequencing could not identify the cause of her congenital anomalies. However, Sanger sequencing revealed a compound heterozygous mutation within RNU4ATAC (NR_023343.1:n.[50G > A];[55G > A]). Immunological findings showed decreases in total lymphocytes, CD4+ T cells, and T cell regenerative activity. Furthermore, antibodies against varicella-zoster, rubella, measles, mumps, and influenza were very low or negative despite having received vaccinations for these viruses. HHV-6 IgG antibodies were also undetected. DISCUSSION The patient here exhibited a marked MOPD I phenotype complicated by various immunodeficiencies. Previous studies have not demonstrated immunodeficiency comorbidities within MOPD I subjects, but this report suggests an evident immunodeficiency in MOPD I. Patients with MOPD I should be treated with one of the immunodeficiency syndromes.

中文翻译：

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与 Roifman 综合征相比，I 型小头骨发育不良原始侏儒症患者的免疫缺陷

背景小头骨发育不良原始侏儒症 I 型（MOPD I，也称为 Taybi-Linder 综合征）是一种罕见的遗传疾病，与严重的宫内发育迟缓、身材矮小、小头畸形、脑异常、四肢发育迟缓和早期死亡率相关。RNU4ATAC 是导致这种疾病的基因，它不编码蛋白质，而是编码 U4atac 小核 RNA (snRNA)，这是次要剪接体的重要组成部分。Roifman 综合征是 MOPD I 的等位基因疾病，其特征是免疫缺陷并发症。病例报告 本文描述的患者是一名 18 岁的女性，患有先天性侏儒症和小头畸形，并伴有脑结构异常。她在一岁时患有人类疱疹病毒 6 (HHV-6) 相关的急性坏死性脑病，此后导致严重的精神运动障碍。使用基因微阵列和全外显子组测序的基因分析无法确定她先天性异常的原因。然而，Sanger 测序揭示了 RNU4ATAC 内的复合杂合突变（NR_023343.1:n.[50G > A];[55G > A]）。免疫学发现显示总淋巴细胞、CD4+ T 细胞和 T 细胞再生活性降低。此外，尽管接种了这些病毒的疫苗，但针对水痘-带状疱疹、风疹、麻疹、腮腺炎和流感的抗体非常低或呈阴性。HHV-6 IgG 抗体也未检测到。讨论 这里的患者表现出明显的 MOPD I 表型，并伴有各种免疫缺陷。以前的研究没有证明 MOPD I 受试者存在免疫缺陷合并症，