case_images: PMC7475762_01
case_images: PMC7475762_02
case_images: Photographs and MRI of the patient. (a) A front view of the patient showing bitemporal bulbous nose, wide nasal base, and bitemporal narrowing. (b) A side view of the patient showing microcephaly, micrognathia, and retrognathia. (c) Perineum showing hypoplastic scrotum. (d) A sagittal fluid-attenuated inversion recovery (FLAIR) image showing corpus callosum agenesis. (e) Sagittal T2-weighted MRI images of the knees showing absent patellar cartilages. (f) A coronal 3D T2-weighted image showing bilateral renal pelvic dilation.
case_images: CRIG2020-1731720.001.jpg
case_images: PMC7475762_02_CRIG2020-1731720.001.jpg
case_images: fig1
case_images: He had dysmorphic features including microcephaly, bulbous nose, wide nasal base, bitemporal narrowing, micrognathia, and retrognathia (Figures 1(a) and 1(b)). Additionally, limited range of motion in both knees, left clubfoot, and hypoplastic scrotum were recognized (Figure 1(c)), and he had dimples in the bilateral knees. Ultrasonography and magnetic resonance imaging confirmed corpus callosum agenesis, cerebral ventricle dilation, bilateral moderate hydronephrosis, and bilateral missing patellar cartilage (Figures 1(d)-1(f)).
case_images: Electrocardiogram (ECG) and echocardiogram of the patient. (a) The 12-lead ECG of the patient showing complete right bundle branch block and right axis deviation. (b) Apical four-chamber view at birth showing the intramural cavity of the trabecular ventricular septum. (c) Doppler ultrasonography at birth showing to-and-fro communication between the right ventricle and cardiac intramural cavity. (d) Apical four-chamber view at 1 month of age showing trabecular septum thinning and flash (white arrow). IC, intramural cavity; RA, right atrium; RV, right ventricle; LA, left atrium; LV, left ventricle.
case_images: CRIG2020-1731720.002.jpg
case_images: PMC7475762_02_CRIG2020-1731720.002.jpg
case_images: fig2
case_images: Electrocardiogram (ECG) showed sinus rhythm with complete right bundle branch block and right axis deviation (Figure 2(a)). Moreover, Doppler ultrasonography depicted three to-and-fro communications (2-3 mm) between the right ventricle and cavity (Figures 2(b) and 2(c)). The intramural cavity disappeared at 1 month of age, but the thinning and flash of the trabecular septum, at which the cavity had existed, remained (Figure 2(d)).
case_images: Genomic sequence of the patient. (a) Sanger sequence of KAT6B in the patient showing the de novo heterozygous c.3769_3772 deletion in exon 18. (b) Subcloning of mutated alleles of KAT6B in the patient showing the de novo heterozygous c.3769_3772 deletion in exon 18.
case_images: CRIG2020-1731720.003.jpg
case_images: PMC7475762_02_CRIG2020-1731720.003.jpg
case_images: fig3
case_images: Inc., Shiga, Japan). In exon 18, a de novo 4 bp deletion was detected, c.3769_3772delTCTA, leading to a frameshift and premature stop codon (p.Lys1258Glyfs*13) (Figures 3(a) and 3(b)).