To delineate the phenotype associated with biallelic ATAD1 variants.

We describe 2 new patients with ATAD1-related disorder diagnosed by whole-exome sequencing and compare their phenotype to 6 previous patients.

Patients 1 and 2 had a similar distinctive phenotype comprising congenital stiffness of limbs, absent spontaneous movements, weak sucking, and hypoventilation. Both had absent brainstem evoked auditory responses (BEARs). Patient 1 carried the homozygous p.(His357Argfs*15) variant in ATAD1. In the light of the finding in patient 1, a second reading of exome data for patient 2 revealed the novel homozygous p.(Gly128Val) variant.

Analysis of the phenotypes of these 2 patients and of the 6 previous cases showed that biallelic ATAD1 mutations are responsible for a unique congenital encephalopathy likely comprising absent BEAR, different from hyperekplexia and other conditions with neonatal hypertonia.

描绘与双等位基因ATAD1变体相关的表型。

我们描述了 2 名通过全外显子组测序诊断出患有ATAD1相关疾病的新患者，并将他们的表型与 6 名以前的患者进行了比较。

患者 1 和 2 具有相似的独特表型，包括先天性四肢僵硬、缺乏自发运动、吸吮无力和通气不足。两者都没有脑干诱发听觉反应（BEAR）。患者 1 在 ATAD1 中携带纯合 p.(His357Argfs*15) 变体。根据患者 1 的发现，对患者 2 的外显子组数据的第二次阅读揭示了新的纯合 p.(Gly128Val) 变体。

对这 2 例患者和 6 例先前病例的表型分析表明，双等位基因ATAD1突变是导致一种独特的先天性脑病的原因，可能包括 BEAR 缺失，不同于过度惊厥和其他新生儿高张力的情况。