Ochoa Molina Maria Fernanda, Poggi Helena, De Toro Valeria, Mendoza Carolina, Hussain Khalid
Endocrinology Unit, Division of Pediatrics, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile Santiago, Chile.
Department of Pediatric Gastroenterology and Nutrition, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
AACE Clin Case Rep. 2021 Nov 27;8(3):109-112. doi: 10.1016/j.aace.2021.11.006. eCollection 2022 May-Jun.
BACKGROUND/OBJECTIVE: AKT2 is a serine/threonine kinase that plays a key role in regulating insulin signaling. The phenotype related to the gain-of-function alteration in the gene (c.49G>A, p.Glu17Lys) has been described in 5 patients with clinical findings that mimic hyperinsulinemic hypoglycemia but with undetectable levels of insulin and C-peptide. One of the reports highlights the facial dysmorphic features. We report the case of a new patient with the same activating alteration leading to autonomous activation of the insulin signaling pathway and dysmorphic features. Moreover, to our knowledge, this is the first report using waxy maize heat-modified starch (WMHMS) in this condition.
A previously healthy child was evaluated at 6 months of age for episodes of hypoglycemia. The laboratory test results for the critical samples showed hypoketotic hypoglycemia (glucose level, 2.16 mmol/L [38 mg/dL]) with undetectable levels of insulin (<0.2 mU/L) and C-peptide (<0.033 nmol/L [reference range, 0.37-1.47 nmol/L]). Physical examination revealed hypertelorism, prominent proptosis of the eyes, a flat nasal bridge, delayed psychomotor development, and postnatal symmetrical overgrowth. The genetic study of showed a pathogenic variant (c.49G>A, p.Glu17Lys). To achieve euglycemia, a diet of regular uncooked cornstarch (UCCS) carbohydrate was started. Subsequently, waxy maize heat-modified starch (WMHMS; Glycosade Vitaflo) was used to increase the fasting period to 4 hours. However, we did not find any advantages in comparison with UCCS.
The range of phenotypes of this gain-of-function alteration in may be broad, including dysmorphic features, although the patients harbor the same pathogenic variant.
Regarding the treatment, we observed a similar response with WMHMS compared with UCCS, with no adverse effects.
背景/目的：AKT2是一种丝氨酸/苏氨酸激酶，在调节胰岛素信号传导中起关键作用。该基因功能获得性改变（c.49G>A，p.Glu17Lys）相关的表型已在5例患者中得到描述，这些患者的临床表现类似高胰岛素血症性低血糖，但胰岛素和C肽水平检测不到。其中一份报告强调了面部畸形特征。我们报告了一例新患者，其具有相同的激活改变，导致胰岛素信号通路自主激活和畸形特征。此外，据我们所知，这是在这种情况下首次使用糯玉米热改性淀粉（WMHMS）的报告。
一名此前健康的儿童在6个月大时因低血糖发作接受评估。关键样本的实验室检测结果显示为低酮性低血糖（血糖水平，2.16 mmol/L [38 mg/dL]），胰岛素水平检测不到（<0.2 mU/L），C肽水平检测不到（<0.033 nmol/L [参考范围，0.37 - 1.47 nmol/L]）。体格检查发现眼距增宽、眼球明显突出、鼻梁扁平、精神运动发育迟缓以及出生后对称性过度生长。基因研究显示存在一个致病变异（c.49G>A，p.Glu17Lys）。为实现血糖正常，开始给予常规生玉米淀粉（UCCS）碳水化合物饮食。随后，使用糯玉米热改性淀粉（WMHMS；Glycosade Vitaflo）将禁食期延长至4小时。然而，与UCCS相比，我们未发现任何优势。
尽管患者携带相同的致病变异，但这种功能获得性改变的表型范围可能很广，包括畸形特征。
关于治疗，我们观察到与UCCS相比，WMHMS的反应相似，且无不良反应。
