Prenatal diagnosis of microcephaly with simplified gyral pattern: series of eight cases

Microcephaly with simplified gyral pattern (MSG) is an intrinsic genetic central nervous system disorder, characterized by microcephaly (a reduction of brain volume) and a simplified gyral pattern (a reduced number of gyri and shallow sulci associated with normal cortical thickness and neuroanatomical architecture), related to a reduced number of neuronal progenitors in the germinal matrix. We report the first prenatal series of MSG and define the prenatal imaging pattern, which should inform diagnosis and guide prenatal counseling in cases of fetal microcephaly. In this single-center retrospective study of fetuses with MSG, we assessed features on ultrasound and magnetic resonance imaging (MRI), as well as genetic and neuropathological/postnatal data. We included eight patients who had been referred following observation of microcephaly. Ultrasound examination confirmed microcephaly, with a mean growth delay in head circumference of 3.4 weeks, associated with both a lack of gyration and a lack of opercularization of the Sylvian fissure and without any extracephalic anomaly. Fetal brain MRI confirmed lack of gyration with normal cortical thickness and normal intensity of the white matter in all cases. These MRI features led to exclusion of migration/corticogenesis disorders (lissencephaly/polymicrogyria), instead suggesting MSG. The posterior fossa was normal in seven of the eight cases. The corpus callosum was thin in four cases, hypoplastic in two and dysgenetic in two. In four cases, the pregnancy was terminated. The diagnosis of MSG was confirmed from neuropathological and postnatal MRI data. MSG was associated with a genetic diagnosis of RTTN (n = 1) and ASPM (n = 2) biallelic variants in three of the six cases in which genetic work-up was performed. Mild or moderate intellectual deficit with speech delay was present in the three surviving children who were at least 5 years of age at their last examination, without seizures. In conclusion, in the presence of isolated fetal microcephaly with lack of gyration on ultrasound, fetal cerebral MRI is key to diagnosing MSG, which, in the majority of cases, affects the supratentorial space exclusively, and to ruling out other cortical malformations that show a similar sonographic pattern. In addition to imaging, genetic assessment may guide prenatal counseling, since the prenatal prognosis of MSG is different from that of both diffuse polymicrogyria and lissencephaly. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

GRM7-related disorder: five additional patients from three independent families and review of the literature

Developmental and epileptic encephalopathies (DEEs) refer to a group of severe epileptic syndromes characterized by seizures as well as a developmental delay which can be a consequence of the underlying etiology and/or the epileptic encephalopathy. The genes responsible for DEEs are numerous and their number is increasing since the availability of Next-Generation Sequencing. Pathogenic variants in GRM7, encoding the metabotropic glutamate receptor 7, were recently shown as a cause of a severe DEE with autosomal recessive inheritance. To date, only ten patients have been reported in the literature, generally with severe phenotypes including early-onset epilepsy, microcephaly, brain anomalies, and spasticity. We report here 5 patients from 3 independent families with biallelic variants in the GRM7 gene. We review the literature and provide further elements for the understanding of the genotype-phenotype correlation of this rare syndrome.

Percutaneous Sclerotherapy of Large Venous Malformations Using Consecutive Polidocanol and Bleomycin Foam: MR Imaging Volumetric and Quality-of-Life Assessment

PURPOSE

To retrospectively evaluate sclerotherapy using consecutive polidocanol and bleomycin foam (CPBF) for large untreated venous malformations (VMs) and/or those resistant to prior treatment.

MATERIALS AND METHODS

This retrospective study included all patients treated with CPBF for untreated VMs larger than 10 mL and/or refractory to treatment between May 2016 and October 2019. Baseline and follow-up VM volumes were measured on fat-suppressed T2-weighted magnetic resonance (MR) imaging. Outcome was evaluated on postprocedural MR imaging volumetry and by a retrospective survey assessing clinical response and adverse events. Imaging response was considered good for volume reduction from 50% to 70% and excellent for volume reduction ≥70%. Symptoms and quality-of-life (QoL) scores were compared before and after CPBF sclerotherapy.

RESULTS

Forty-five patients (mean age, 16 years; range, 1-63 years; 25 males) with 57 VMs were analyzed and treated by 80 sclerotherapy. Sixty percent (27 of 45) of patients had undergone prior treatment for VM. Median VM volume was 36.7 mL (interquartile range, 84 mL) on pretherapy MR imaging. Good and excellent results after the last sclerotherapy were achieved in 36% (16 of 45) and 29% (13 of 45) of patients, respectively, corresponding to a decrease of >50% in 60% (34 of 57) of VMs. QoL score increased by at least 3 points, regardless of initial symptoms. Most patients did not desire additional sclerotherapy owing to near complete symptomatic relief, even for patients who did not achieve a good response. Swelling, pain, and motor impairment scores significantly improved after CPBF. Adverse events included fever (44%, 15 of 34) and nausea/vomiting (29%, 10 of 34).

CONCLUSIONS

CPBF sclerotherapy represents an effective therapy for large and/or refractory VMs with minimal adverse events.

Plea for systematic prenatal genes panel testing when facing isolated craniosynostosis on fetal imaging

BACKGROUND

Prenatal diagnosis of craniosynostosis remains rare and challenging, easier in syndromes with craniosynostosis due to the association with other sonographic anomalies. Crouzon syndrome is the most frequent syndrome with craniosynostosis but is difficult to detect antenatally because of mild skull deformation without specific associated anomaly during gestation.

CASE

This report presents the case of a fetus with Crouzon syndrome related to the variant c.1646A>C in exon 14 of the FGFR2 gene and presenting with apparently isolated scaphocephaly on fetal US.

CONCLUSION

This observation supports the interest of systematic prenatal panel genes testing when facing an apparently isolated craniosynostosis diagnosed on fetal imaging, even if non-syndromic craniosynostosis are much more frequent in such situation.

TEACHING POINTS

Syndromic craniosynostosis can appear as apparently isolated form on fetal imaging. Systematic prenatal panel genes testing can be contributive even when facing an apparently isolated craniosynostosis on fetal imaging.

Pediatric urolithiasis: what can pediatricians expect from radiologists?

The incidence of urolithiasis in children has increased over the two last decades. Urolithiasis formation results from urine oversaturation following insufficient water intake, urinary obstruction (notably in cases of congenital uropathies), excess production of an insoluble compound, or imbalance between crystallization promoters and inhibitors. Whereas most urolithiases in adults occur secondary to environmental factors, in children, secondary causes are far more frequent, and 15% are related to genetic causes, most often monogenic. This is especially true in recurrent forms, with early and rapid progression and bilateral stones, and in cases of familial history or consanguinity. Because of differing clinical management, one should rule out cystinuria, primary hyperoxaluria and renal tubular acidosis, among other causes of urolithiasis. As such, a complete biochemical evaluation must be performed in all cases of pediatric urolithiasis, even in cases of an underlying uropathy. Ultrasound examination is the first-line modality for imaging pediatric urolithiasis, allowing both diagnosis (urolithiasis and its complications) and follow-up. US examination should also explore clues to an underlying cause of urolithiasis. This review is focused on the role of imaging in the management and etiological assessment of pediatric urolithiasis. Radiologists play an important role in pediatric urolithiasis, facilitating diagnosis, follow-up and surgical management. A trio of clinicians (pediatric nephrologist, pediatric surgeon, pediatric radiologist) is thus necessary in the care of these pediatric patients.

Predicting Outcome of Congenital Cytomegalovirus Infection by Differentiating and Revisiting Severe versus Mild Prenatal Imaging Features

INTRODUCTION

Our objective was to evaluate the outcome of fetuses with first- and second-trimester fetal cytomegalovirus infection (CMVi) according to prenatal imaging patterns, especially fetuses presenting with mild imaging features (MF), being currently of uncertain prognosis.

MATERIAL AND METHODS

In a retrospective study of 415 suspected CMVi cases, 59 cases were confirmed. Among prenatal imaging features, microcephaly, cortical disorder, and cerebellar hypoplasia as well as severe IUGR and fetal hydrops were considered as severe imaging features (SF). Other imaging features were considered as MF. Postnatal outcome was classified as "normal outcome," "mild sequelae" characterized mainly by sensorineural disorder (SND) and "severe sequelae" characterized by cognitive impairment.

RESULTS

Only first-trimester (T1) and second-trimester (T2) CMVi cases were included in our study (n = 49) since all third-trimester cases (n = 10) had normal imaging and outcome. Sixteen fetuses had normal prenatal imaging and normal outcome, except one showing SND. Abnormal ultrasound findings were present in 33 fetuses, including SF noted in 16 fetuses, related exclusively to first-trimester CMVi. Termination of pregnancy was performed in 18 cases. Twelve first-trimester infected fetuses presented SF, whereas 6 fetuses (T1: n = 5, T2: n = 1) presented isolated MF. Four fetal deaths were encountered. Live-born babies with abnormal imaging included 10 fetuses with MF and one with SF. Among the 10 live babies with isolated MF, SND was encountered in 5 cases, whereas 5 children demonstrated normal outcome. Overall, 50% of our babies showing MF suffered from SND. No case of cognitive disorders was reported in babies showing only MF.

CONCLUSION

SF were encountered only in first-trimester CMVi and should be distinguished from MF. Among our 10 live babies with prenatal MF following first- or second-trimester infection, 50% showed SND, whereas none presented severe sequelae. In 16 fetuses displaying normal fetal imaging, SND was encountered in one first-trimester case (6%).

Hemidystonia with polymicrogyria is part of ATP1A3-related disorders

INTRODUCTION

Pathogenic variants in ATP1A3 cause various phenotypes of neurological disorders, including alternating hemiplegia of childhood 2, CAPOS syndrome (cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss) and rapid-onset dystonia-parkinsonism (RDP). Early developmental and epileptic encephalopathy has also been reported. Polymicrogyria has recently been added to the phenotypic spectrum of ATP1A3-related disorders.

CASE REPORT

We report here a male patient with early developmental delay who at 12 months presented dystonia of the right arm which evolved into hemidystonia at the age of 2. A cerebral MRI showed bilateral perisylvian polymicrogyria with intact basal ganglia. Whole-exome and whole-genome sequencing analyses identified a de novo new ATP1A3 missense variant (p.Arg914Lys) predicted pathogenic. Hemidystonia was thought not to be due to polymicrogyria, but rather a consequence of this variant.

CONCLUSION

This case expands the phenotypic spectrum of ATP1A3-related disorders with a new variant associated with hemidystonia and polymicrogyria and thereby, suggests a clinical continuum between the different phenotypes of this condition.

New insights in craniovertebral junction MR changes leading to stenosis in children with achondroplasia

PURPOSE

To characterize natural history and early changes of craniovertebral junction stenosis in achondroplasia correlating with clinical and radiological outcome.

METHODS

Retrospective measures on craniovertebral junction were performed blindly, on sagittal T2-weighted images, in 21 patients with achondroplasia referred from 2008 to 2020. Clinical and polysomnography data were retrospectively collected. Each patient was paired for age and gender with four controls. Wilcoxon means comparison or Student's t-tests were applied.

RESULTS

Twenty-one patients (11 females, from 0.1 to 39 years of age) were analyzed and paired with 84 controls. A craniovertebral junction stenosis was found in 11/21 patients (52.4%), all before the age of 2 years. Despite a significant reduction of the foramen magnum diameter (mean ± SD: patients 13.6 ± 6.2 mm, controls 28.5 ± 4.7 mm, p < .001), craniovertebral junction stenosis resulted from the narrowing of C2 dens-opisthion antero-posterior diameter (8.7 ± 3.9 mm vs 24.6 ± 5.1 mm, p < .001). Other significant changes were opisthion anterior placement (-0.4 ± 2.8 mm vs 9.4 ± 2.3 mm, p < .001), posterior tilt of C2 (46.2 ± 13.7° vs 31.6 ± 7.9°, p < .001) and of C1 (15.1 ± 4.3° vs 11.9 ± 5.0°, p = 0.01), and dens thickening (9.4 ± 2.2 mm vs 8.5 ± 2.1 mm, p = 0.03), allowing to define three distinguishable early craniovertebral junction patterns in achondroplasia. All children with C2-opisthion antero-posterior diameter of more than 6 mm had a better clinical and radiological outcome.

CONCLUSION

Craniovertebral junction in achondroplasia results from narrowing between C2 dens and opisthion related to anterior placement of opisthion, thickening of C2 dens, and posterior tilt of C1-C2. A threshold of 6 mm for dens-opisthion sagittal diameter seems to correlate with clinical and radiological outcome.

PRENATAL IMAGING FEATURES RELATED TO RAC3 PATHOGENIC VARIANT AND DIFFERENTIAL DIAGNOSES

This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved. What's already known about this topic? Six individuals between 5- and 19-year-old were reported with pathogenic variants in RAC3 responsible for brain malformations involving midline What does this study add? RAC3-fetopathy is associated with fetal akinesia deformation sequence, and complex brain malformations including corpus callosum agenesis, diencephalosynapsis, kinked brainstem, and vermian hypoplasia The differential diagnoses with prenatal kinked brainstem include fetopathies related to KIAA1109, L1CAM, Walker-Warburg syndrome and tubulinopathies. The present report adds the RAC3 related condition to this list.

Prenatal diagnosis of Aicardi syndrome based on a suggestive imaging pattern: A multicenter case-series

Objectives

To characterize a suggestive prenatal imaging pattern of Aicardi syndrome using ultrasound and MR imaging.

Methods

Based on a retrospective international series of Aicardi syndrome cases from tertiary centers encountered over a 20‐year period (2000–2020), we investigated the frequencies of the imaging features in order to characterize an imaging pattern highly suggestive of the diagnosis.

Results

Among 20 cases included, arachnoid cysts associated with a distortion of the interhemispheric fissure were constantly encountered associated with complete or partial agenesis of the corpus callosum (19/20, 95%). This triad in the presence of other CNS disorganization, such as polymicrogyria (16/17, 94%), heterotopias (15/17, 88%), ventriculomegaly (14/20, 70%), cerebral asymmetry [14/20, 70%]) and less frequently extra‐CNS anomaly (ocular anomalies [7/11, 64%], costal/vertebral segmentation defect [4/20, 20%]) represent a highly suggestive pattern of Aicardi syndrome in a female patient.

Conclusion

Despite absence of genetic test to confirm prenatal diagnosis of AS, this combination of CNS and extra‐CNS fetal findings allows delineation of a characteristic imaging pattern of AS, especially when facing dysgenesis of the corpus callosum.

What is already known about this topic?

Aicardi syndrome (AS) is a rare developmental encephalopathy, characterized by the classic triad of infantile spasms, agenesis of the corpus callosum, and chorioretinal lacunae

As the genetic etiology of AS is unknown and its classic triad cannot be extrapolated to prenatal diagnosis, to establish a prenatal imaging pattern is of major interest

What does this study add?

We confirmed and completed a prenatal imaging pattern highly suggestive of AS, based on the most frequent features encountered in a large series: arachnoid cysts associated with a distortion of the interhemispheric fissure, agenesis of the corpus callosum, cortical malformations and heterotopias, and less frequently extra‐CNS anomaly (ocular anomalies, costal/vertebral segmentation defect)

Description of a novel patient with the TRPM3 recurrent p.Val837Met variant

De novo heterozygous missense mutations in TRPM3 have been shown to cause developmental and epileptic encephalopathies (DEE). It is a very rare condition, as only 9 patients have been described to date. We report here a novel patient carrying the recurrent p.Val837Met variant and presenting new clinical features, such as trigonocephaly, expanding the phenotypical spectrum of the disease.

Prenatal Imaging Features and Postnatal Outcome of Short Corpus Callosum: A Series of 42 Cases

OBJECTIVES

Our goal was to provide a better understanding of isolated short corpus callosum (SCC) regarding prenatal diagnosis and postnatal outcome.

METHODS

We retrospectively reviewed prenatal and postnatal imaging, clinical, and biological data from 42 cases with isolated SCC.

RESULTS

Prenatal imaging showed SCC in all cases (n = 42). SCC was limited to rostrum and/or genu and/or splenium in 21 cases, involved body in 16 cases, and was more extensive in 5 cases. Indirect imaging features included typical buffalo horn ventricles (n = 14), septal dysmorphism (n = 14), parallel lateral ventricles (n = 12), and ventriculomegaly (n = 4), as well as atypical features in 5 cases. SCC was associated with interhemispheric cysts and pericallosal lipomas in 3 and 6 cases, respectively. Aneuploidy was found in 2 cases. Normal psychomotor development, mild developmental disorders, and global developmental delay were found in 70, 15, and 15% of our cases, respectively.

CONCLUSIONS

SCC should be investigated to look for pericallosal lipoma and typical versus atypical indirect features of corpus callosum agenesis (CCA). Prenatal counselling should be guided by imaging as well as clinical and genetic context. Outcome of patients with SCC was similar to the one presenting with complete CCA.

SPEN haploinsufficiency causes a neurodevelopmental disorder overlapping proximal 1p36 deletion syndrome with an episignature of X chromosomes in females

Deletion 1p36 (del1p36) syndrome is the most common human disorder resulting from a terminal autosomal deletion. This condition is molecularly and clinically heterogeneous. Deletions involving two non-overlapping regions, known as the distal (telomeric) and proximal (centromeric) critical regions, are sufficient to cause the majority of the recurrent clinical features, although with different facial features and dysmorphisms. SPEN encodes a transcriptional repressor commonly deleted in proximal del1p36 syndrome and is located centromeric to the proximal 1p36 critical region. Here, we used clinical data from 34 individuals with truncating variants in SPEN to define a neurodevelopmental disorder presenting with features that overlap considerably with those of proximal del1p36 syndrome. The clinical profile of this disease includes developmental delay/intellectual disability, autism spectrum disorder, anxiety, aggressive behavior, attention deficit disorder, hypotonia, brain and spine anomalies, congenital heart defects, high/narrow palate, facial dysmorphisms, and obesity/increased BMI, especially in females. SPEN also emerges as a relevant gene for del1p36 syndrome by co-expression analyses. Finally, we show that haploinsufficiency of SPEN is associated with a distinctive DNA methylation episignature of the X chromosome in affected females, providing further evidence of a specific contribution of the protein to the epigenetic control of this chromosome, and a paradigm of an X chromosome-specific episignature that classifies syndromic traits. We conclude that SPEN is required for multiple developmental processes and SPEN haploinsufficiency is a major contributor to a disorder associated with deletions centromeric to the previously established 1p36 critical regions.

Two different prenatal imaging cerebral patterns of tubulinopathy

To illustrate the prenatal cerebral imaging features associated with tubulinopathy, we report on five affected fetuses from unrelated families, with a de-novo heterozygous variant in a tubulin gene (TUBA1A, TUBB2B or TUBB3). We identified two distinct prenatal imaging patterns related to tubulinopathy: a severe form, characterized by enlarged germinal matrices, microlissencephaly and a kinked brainstem; and a mild form which has not been reported previously in the prenatal literature. The latter form is associated with non-specific features, including an asymmetric brainstem, corpus callosal dysgenesis, a lack of Sylvian fissure operculization and distortion of the anterior part of the interhemispheric fissure with subsequent impacted medial borders of the frontal lobes, the combination of which, in the absence of additional extracerebral anomalies, is highly suggestive of tubulinopathy. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Intermittent Bi-Daily Sub-cutaneous Teriparatide Administration in Children With Hypoparathyroidism: A Single-Center Experience

Introduction: The use of teriparatide has been reported in children with hypoparathyroidism as an investigational physiologic replacement therapy. Methods: We aimed to retrospectively report our pediatric experience of bi-daily sub-cutaneous teriparatide. Results are presented as median (25th-75th quartile). As part of the routine follow-up of these patients with hypoparathyroidism, total calcium at H0 (i.e., just before injection) and H4 (i.e., 4 h after teriparatide injection) and other biomarker parameters were regularly assessed. Results: At a median age of 10.7 (8.1-12.6) years, an estimated glomerular filtration rate (eGFR) of 110 (95-118) mL/min/1.73 m², calcium levels of 1.87 (1.81-1.96) mmol/L and an age-standardized phosphate of 3.8 (2.5-4.9) SDS, teriparatide therapy was introduced in 10 patients at the dose of 1.1 (0.7-1.5) μg/kg/day (20 μg twice daily), with further adjustment depending on calcium levels. Six patients already displayed nephrocalcinosis. Severe side effects were reported in one child: two episodes of symptomatic hypocalcemia and one of iatrogenic hypercalcemia; one teenager displayed dysgueusia. Calcium levels at H0 did not significantly increase whilst calcium at H4 and phosphate levels significantly increased and decreased, respectively. After 12 months, eGFR, calcium and age-standardized phosphate levels were 108 (90-122) mL/min/1.73 m², 2.36 (2.23-2.48) mmol/L, 0.5 (-0.1 to 1.5), and 68 (63-74) nmol/L, respectively, with a significant decrease in phosphate levels (p = 0.01). Urinary calcium and calcium/creatinine ratio remained stable; no nephrolithiasis was observed but two moderate nephrocalcinosis appeared. Conclusion: Intermittent teriparatide therapy significantly improves calcium and phosphate control, without increasing calciuria. It appears to be safe and well-tolerated in children.

[Microlissencephaly due to pathogenic variants of NDE1: from pathology to normal brain development]

Pathogenic variants of the gene NDE1 (Nuclear Distribution Element 1) in humans lead to microlissencephaly which associates a reduced head circumference and a simplified gyration. Microlissencephaly is the most severe deficit of neurogenesis described to date but its precise physiopathological mechanism is not yet well known. The NDE1 gene encodes a phosphoprotein that is essential to neurogenesis and that is expressed in various cell compartments of neuroblasts. More than 60 interaction partners with NDE1 have been reported, notably various proteins involved in formation of the mitotic spindle, in ciliation, in genome protection of dividing neuroblasts or even in apoptosis (like LIS1, dynein or cohesin), which are all avenues that we explore in this review.

A novel lethal recognizable polymicrogyric syndrome caused by ATP1A2 homozygous truncating variants

Polymicrogyria is a heterogeneous malformation of cortical development microscopically defined by an excessive folding of the cortical mantle resulting in small gyri with a fused surface. Polymicrogyria is responsible for a wide range of neurological symptoms (e.g. epilepsy, intellectual disability, motor dysfunction). Most cases have a supposed environmental clastic vascular or infectious origin but progress in genomics has revealed new monogenic entities. We report four cases from two independent families sharing a common recognizable lethal syndromic polymicrogyria of autosomal recessive inheritance. Beyond diffuse polymicrogyria detected prenatally, pathological examination revealed a common pattern associating meningeal arterial calcifications, necrotic and calcified areas in basal ganglia, dentato-olivary dysplasia and severe hypoplasia/agenesis of the pyramidal tracts. In all affected cases, exome sequencing showed a pathogenic homozygous nonsense ATP1A2 variant. This resulted in absence of immunodetectable ATP1A2 protein in two brains analysed. ATP1A2 encodes the alpha-2 isoform of the Na+/K+-ATPase, which is highly expressed in brain tissues and has previously been related to familial hemiplegic migraine (MIM#602481) and alternating hemiplegia of childhood (MIM#104290). Through the description of this genetic entity, we emphasize the possibility of dual mode of transmission for disease-causing genes and provide the key neuropathological features that should prompt geneticists to test for mutations in the ATP1A2 gene.

Novel truncating and missense variants extending the spectrum of EMC1-related phenotypes, causing autism spectrum disorder, severe global development delay and visual impairment

The EMC1 gene, located on 1p36.13, encodes the subunit 1 of the endoplasmic reticulum-membrane protein complex, a highly conserved and ubiquitous multiprotein transmembrane complex. Pathogenic monoallelic and biallelic variants in EMC1 in humans have been reported only in six families, causing isolated visual impairment or in association with psychomotor retardation and cerebellar atrophy. We report a ten-year-old boy, born to unrelated parents, with early-onset severe global development delay due to novel EMC1 biallelic pathogenic variants. A truncating variant, p.(Tyr378*) and a missense variant, p.(Phe953Ser), located in exon 11 and 23 of EMC1 gene respectively, have been found by reanalysis of exome sequencing data. The proband's phenotype included several signs that overlap with the phenotype of previously reported patients, associating severe global developmental delay, abnormal ophthalmological examination, and postnatal slow-down of the head circumference growth. Some distinguishing clinical signs were observed in comparison to patients from literature, such as autism spectrum disorder, absence of seizures, scoliosis or facial dysmorphic features, thus extending the spectrum of EMC1-related phenotypes. Similarly, brain MRI, performed at 2 years, showed normal cerebellar volume and structure, whereas cerebellar atrophy was described in literature. Moreover, difficulties of clinical differential diagnosis between EMC1-associated disease and other etiologies of global development delay support the importance of large-scale genetic investigations. Our diagnostic approach, through reanalysis of exome sequencing data, highlights the importance of reconsidering initial negative results for patients with a strong suspicion of genetic disease, and to update analytic pipelines in order to improve the diagnostic yield of exome sequencing.