Severe Psychomotor Retardation Research Articles

Characterization of the Epileptogenic Phenotype and Response to Antiseizure Medications in Lissencephaly Patients.

Patients with lissencephaly typically present with severe psychomotor retardation and drug-resistant seizures. The aim of this study was to characterize the epileptic phenotype in a genotypically and radiologically well-defined patient cohort and to evaluate the response to antiseizure medication (ASM). Therefore, we retrospectively evaluated 47 patients of five genetic forms (LIS1/PAFAH1B1, DCX, DYNC1H1, TUBA1A, TUBG1) using family questionnaires, standardized neuropediatric assessments, and patients' medical reports. All but two patients were diagnosed with epilepsy. Median age at seizure onset was 6 months (range: 2.1-42.0), starting with epileptic spasms in 70%. Standard treatment protocols with hormonal therapy (ACTH or corticosteroids) and/or vigabatrin were the most effective approach for epileptic spasms, leading to seizure control in 47%. Seizures later in the disease course were most effectively treated with valproic acid and lamotrigine, followed by vigabatrin and phenobarbital, resulting in seizure freedom in 20%. Regarding psychomotor development, lissencephaly patients presenting without epileptic spasms were significantly more likely to reach various developmental milestones compared to patients with spasms. Classic lissencephaly is highly associated with drug-resistant epilepsy starting with epileptic spasms in most patients. The standard treatment protocols for infantile epileptic spasms syndrome lead to freedom from seizures in around half of the patients. Due to the association of epileptic spasms with an unfavorable course of psychomotor development, early and reliable diagnosis and treatment of spasms should be pursued. For epilepsies occurring later in childhood, ASM with valproic acid and lamotrigine, followed by vigabatrin and phenobarbital, appears to be most effective.

Lissencephaly: presentation of a clinical case of LIS 1 with a diagnosis confirmed by MLPA method and indications for rehabilitation treatment in childhood

ABSTRACT Lissencephaly is a very rare clinical condition that affects the formation of the brain and causes severe psychomotor retardation, convulsions and muscular spasticity or hypotonia, often also associated with respiratory problems, facial dysmorphisms, abnormalities of the fingers and toes and difficulty swallowing resulting in reduced life expectancy. The clinical case described in the following article demonstrates the diagnostic process and rehabilitation treatment of a patient through a narrative review of the scientific literature and the presentation of this condition in order to provide indications to guide rehabilitation treatment in childhood.

Molecular Dynamic Simulations to Determine Individualized Therapy: Tetrabenazine for the GNAO1 Encephalopathy E246K Variant.

GNAO1 encephalopathy is characterized by severe hypotonia, psychomotor retardation, epilepsy, and movement disorders. Genetic variations in GNAO1 have been linked to neurological symptoms including movement disorders like dystonia. The correlation between the E246K mutation in the Gα subunit and aberrant signal transduction of G proteins has been established but no data are reported regarding the efficacy of medical treatment with tetrabenazine. Molecular modeling studies were performed to elucidate the molecular mechanisms underlying this mutation. We developed drug efficacy models using molecular dynamic simulations that replicated the behavior of wild-type and mutated proteins in the presence or absence of ligands. We demonstrated that the absence of the mutation leads to normal signal transduction upon receptor activation by the endogenous ligand, but not in the presence of tetrabenazine. In contrast, the presence of the mutation resulted in abnormal signal transduction in the presence of the endogenous ligand, which was corrected by the drug tetrabenazine. Tetrabenazine was identified as a promising therapeutic option for pediatric patients suffering from encephalopathy due to an E246K mutation in the GNAO1 gene validated through molecular dynamics. This is a potential first example of the use of this technique in arare neurological pediatric disease.

RNASEH2C c.194G>A is a Chinese-specific founder mutation in three unrelated patients with Aicardi-Goutières syndrome 3.

Biallelic pathogenic variants in RNASEH2C cause Aicardi-Goutières syndrome 3 (AGS3, MIM #610329), a rare early-onset encephalopathy characterized by intermittent unexplained fever, chilblains, irritability, progressive microcephaly, dystonia, spasticity, severe psychomotor retardation and abnormal brain imaging. Currently, approximately 50 individuals with AGS3 and 19 variants in RNASEH2C have been revealed. Here, we reported the novel clinical manifestations and genotypic information of three unrelated Chinese patients with AGS3 caused by pathogenic variants in RNASEH2C. In addition to three novel missense variants (c.101G>A, p.Cys34Tyr; c.401T>A, p.Leu134Gln and c.434G>T, p.Arg145Leu), one missense variant (c.194G>A, p.Gly65Asp) reoccurred in all patients but was completely absent in South Asian and other ethnicities. Our study expanded the variant spectrum of RNASEH2C and identified RNASEH2C c.194G>A as a Chinese-specific founder mutation. The novel phenotypes, including mouth ulcers, hip dysplasia, retarded dentition and hypogonadism, observed in our patients greatly enriched the clinical characteristics of AGS3.

Fahr´s Syndrome; Pseudohypoparathyroidism Type Ib Masquerading as Epileptic Seizures

Hypocalcaemia of various origin can be manifested by paresthesia, muscle cramps, muscle weakness, syncope, convulsions and even severe psychomotor retardation. Such symptoms can be initially considered as signs of epilepsy. We present a 12-year old boy with partial seizures and basal ganglia calcifications, initially diagnosed as having Fahr´s disease and epilepsy, where severe hypocalcaemia, due to genetically confirmed pseudohypoparathyroidism type Ib was the underlying cause. Excellent clinical improvement was observed after calcium and vitamin D therapy. The basal ganglia calcifications were secondary due to chronic hypocalcaemia, therefore the appropriate diagnosis was pseudohypoparathyroidism type Ib with Fahr´s syndrome, but not Fahr´s disease. In conclusion, the serum evaluation of minerals, especially calcium and phosphate, should be performed in all patients with convulsions, cramps and psychomotor retardation. This is essential in arriving at a proper diagnosis and early initiation of appropriate treatment.

OBSERVATION OF THE NORMAL DEVELOPMENTAL PATTERN OF FETAL CEREBRAL SULCI BETWEEN 18 TO 32 WEEKS OF GESTATIONAL AGE BY USING ULTRASONOGRAPHY - A CORRELATIONAL STUDY BETWEEN TWO MATERNAL AGE GROUPS

Background: Anomalous or absent fetal sulci and gyri may be associated with abnormal brain development and increased incidence of the neurological and psychomotor problems like refractory epilepsy or developmental delay, later in the infant life. Lissencephaly, is a condition with "smooth brain," with the absence of normal convolutions (folds) in the cerebral cortex. Neuronal migration disorders result when the post mitotic neurons fail to migrate from the ventricular zone to the cortical plate, resulting in a wide spectrum of cortical malformations. The most common clinical manifestations include severe psychomotor retardation, developmental delay, refractory seizures, and failure to thrive.
 Aim. The research aims at observing normal developmental pattern of fetal cerebral sulci between 18 to 32 weeks of gestational age by using ultrasonography.
 Material and Methods. This is a Cross-sectional observational study, performed among 110 antenatal women investigated under the Department of Radio Diagnosis, Shri Sathya Sai medical college and research institute, Ammapettai. The appearance and complete formation of sulci and fissures such parieto-occipital sulci, cingulate sulci, calcarine sulci and convexity sulci and also the insula/sylvian fissure were identified.
 Results and Discussion. Parietooccipital fissure wass identified as dot pattern by 18-19 weeks and complete by 24 weeks. Calcarine fissure identified as dot pattern by 18 -19 weeks and almost complete by 22 weeks. Cingulate sulci were identified as dot pattern by 23-24 weeks, with Y pattern appearing by 27-28 weeks and complete by 31-33 weeks. By 19-20 weeks Smooth surface Sylvian fissure was present and predominant till 20-21 weeks. By 22-23 weeks Obtuse angle Sylvian fissure was predominant and by 29-30 weeks Acute angle Sylvian fissure was complete. Convexity sulci was absent till 23 weeks 6 days and started appearing after 24 weeks. The Convexity sulci fully appeared after 28 weeks. The mean Period of Gestation (weeks) of the appearance of Dot, V and Y patterns of each fissure and sulci between the mother of below and above 35 years were not statistically significant.
 Conclusion. Parietooccipital fissure, Sylvian fissure and Calcarine fissure started appearing by 18-19 weeks, and complete by 24 weeks (except Sylvian fissure which was complete by 30 weeks). Convexity and Cingulate sulci started appearing early by 23 weeks, complete by 28 weeks and 33 weeks respectively.

Gamma-Aminobutyric Acid Transaminase (GABA-T) Deficiency in a Consanguineous Saudi Family: A Case Report and Literature Review

AbstractGamma-aminobutyric acid transaminase (GABA-T) deficiency is a rare, autosomal recessive disorder caused by mutations in the 4-aminobutyrate aminotransferase (ABAT) gene, which encodes an enzyme involved in GABA catabolism. It is characterized by severe psychomotor retardation, early-onset epileptic encephalopathy, intractable seizures, hypotonia, hyperreflexia, movement disorder, hypersomnolence, and early childhood mortality. It is associated with elevated free GABA in cerebrospinal fluid (CSF), GABA-T deficiency in cultured lymphoblasts, hypomyelination on brain magnetic resonance imaging (MRI), and elevated GABA level in the basal ganglia on proton magnetic resonance spectroscopy (MRS). Only 14 cases have been published in the literature. A rare case of infantile epileptic encephalopathy caused by GABA-T deficiency resulting from a previously unreported homozygous missense mutation in the ABAT gene is described. Our findings add to the phenotypic, neuroradiological, and genetic spectrum of ABAT mutations.

Clinical and Biological Characteristics of a Griscelli Syndrome Type 2: About a Case Report

Introduction: Griscelli Syndrome (GS) is a rare autosomal recessive genetic disorder, characterized by a partial albinism that can be associated with early-onset severe psychomotor retardation, and normal immune status (type 1), or associated with an immune deficiency (type 2). GS type 2 results from mutations in the RAB27A gene, leading to immune deficiency. GS type 2 has a grave prognosis because of a rapidly fatal macrophage activated syndrome. Case Report: A 3-month-old infant having a family history of first-degree consanguinity in the parents and history of silvery gray hair in two uncles, Admitted to our department for management of a prolonged fever and an anemic syndrome. Hair on the scalp, eyebrows, and eyelashes were silvery gray and had a metallic sheen. The lymphocyte sub typing showed a severe combined immune deficiency. Histological examination of the hair showed enlarged, hyper pigmented basal melanocytes with sparse pigmentation of adjacent keratinocytes in favor of a Griscelli syndrome. The evolution was marked by clinical worsening, respiratory distress. On the biological level, a macrophage activation syndrome was retained in front of a hyperferritinemia, a hypertriglyceridemia and hepatic cytolysis. The patient received broad-spectrum antibiotic therapy, antivirals and antifungals, corticosteroid boluses 3 days in a row and an immunoglobulin infusion. Unfortunately, the patient died of septic shock. Conclusion: Type 2 GS is a rare genetic disease with a poor prognosis, which must be diagnosed early to allow better support. The only curative treatment is bone marrow transplantation.

A nationwide survey of monocarboxylate transporter 8 deficiency in Japan: Its incidence, clinical course, MRI and laboratory findings

BackgroundMonocarboxylate transporter 8 (MCT8) deficiency is an X-linked recessive developmental disorder characterized by initially marked truncal hypotonia, later athetotic posturing, and severe intellectual disability caused by mutations in SLC16A2, which is responsible for the transport of triiodothyronine (T3) into neurons. We conducted a nationwide survey of patients with MCT8 deficiency to clarify their current status. MethodsPrimary survey: In 2016–2017, we assessed the number of patients diagnosed with MCT8 deficiency from 1027 hospitals. Secondary survey: in 2017–2018, we sent case surveys to 31 hospitals (45 cases of genetic diagnosis), who responded in the primary survey. We asked for: 1) perinatal history, 2) developmental history, 3) head MRI findings, 4) neurophysiological findings, 5) thyroid function tests, and 5) genetic test findings. ResultsWe estimated the prevalence of MCT8 deficiency to be 1 in 1,890,000 and the incidence of MCT8 deficiency per million births to be 2.12 (95 % CI: 0.99–3.25). All patients showed severe psychomotor retardation, and none were able to walk or speak. The significantly higher value of the free T3/free T4 (fT3/fT4) ratio found in our study can be a simple and useful diagnostic biomarker (Our value 11.60 ± 4.14 vs control 3.03 ± 0.38). Initial white matter signal abnormalities on head MRI showed recovery, but somatosensory evoked potentials (SEP) showed no improvement, suggesting that the patient remained dysfunctional. ConclusionFor early diagnosis, including in mild cases, it might be important to consider the clinical course, early head MRI, SEP, and fT3/fT4 ratio.

Red cell adenylate kinase deficiency in China: molecular study of 2 new mutations (413G > A, 223dupA)

BackgroundAdenylate kinase (AK) is a monomolecular enzyme widely found in a variety of organisms. It mainly catalyses the reversible transfer of adenosine nucleotide phosphate groups and plays an important role in maintaining energy metabolism. AK deficiency is a rare genetic disorder that is related to haemolytic anaemia. Chronic haemolytic anaemia associated with AK deficiency is a rare condition, and only 14 unrelated families have been reported thus far. Moreover, only 11 mutations have been identified in the AK1 gene, with only 3 cases of psychomotor impairment.Case presentationThe patient was a 3-year-old boy with severe haemolytic anaemia and psychomotor retardation. A molecular study of the patient’s AK gene revealed 2 different mutations: a heterozygous missense mutation in exon 6 (c.413G > A) and a heterozygous frameshift mutation in exon 5 (c.223dupA). Molecular modelling analyses indicated that AK gene inactivation resulted in a lack of AK activity. The patient recovered after regular blood transfusion therapy.ConclusionsAK1 deficiency was diagnosed on the basis of low enzymatic activity and the identification of a mutation in the AK1 gene located on chromosome 9q. Here, we report the first case of moderate red cell AK1 deficiency associated with chronic nonspherocytic haemolytic anaemia (CNSHA) in China. The genetic mutations were confirmed by Sanger sequencing. The variants were classified as pathogenic by bioinformatics tools, such as ACMG/AMP guidelines, Mutation Taster, SIFT, MACP, REVEL and PolyPhen2.2. Based on our evidence and previous literature reports, we speculate that the site of the AK1 gene c.413G > A (p.Arg138His) mutation may be a high-frequency mutation site and the other mutation (c.223dupA) might be related to the neuropathogenicity caused by AK1 deficiency. NGS should be a part of newborn to early childhood screening to diagnose rare and poorly diagnosed genetic diseases as early as possible.

Role of Ultrasonography in the Evaluation of Normal Developmental Pattern of Fetal Cerebral Sulci Between 18 and 32 Weeks of Gestational Age.

BackgroundBrain development is a crucial process of intrauterine life and can be readily visualized on ultrasonography. This study aims to visualize developmental patterns of various fetal cerebral sulci using ultrasonography between 18 and 32 weeks of gestation. Sulci are best visualized on images that are taken perpendicular to their expected course of development. Initially, they appear as small dot/dimple on the brain surface and later develop into a V-shaped indentation and finally deepen to form notch and echogenic line into the brain forming a Y-shaped configuration.Material and methodsThis was a cross-sectional observational study conducted on 241 antenatal mothers with a singleton pregnancy between 18 and 32 weeks of gestational age. Demographic and clinical data were obtained. Ultrasonography was performed using PHILIPS EPIQ 5, a curvilinear probe of frequency 2-5MHz. Sulci/fissures that are reported to appear early on anatomical studies were evaluated, specifically the parieto-occipital fissure, calcarine fissure, cingulate sulci, insula/Sylvian fissure, and convexity sulci. Comparison of the categorical outcomes was performed between study groups using the chi-square test. A p-value of <0.05 was considered statistically significant.ResultsThe study included 241 participants. The mean age of antenatal mothers was 24.09 ± 4.13 years, and the mean fetal gestational age was 24.99 ± 4.13 weeks. Parieto-occipital fissure was the first fissure to develop and was present as a V-shaped indentation at 18 weeks and as a Y-shaped configuration by 21-22 weeks. Calcarine fissure was the next fissure to appear; it appeared as a dot by 18 weeks and developed into a V-shaped indentation by 20 weeks and as a Y-shaped configuration by 23 weeks. All fissures except cingulate sulci had appeared by 20 weeks, and calcarine sulci appeared later in the gestation by 21 weeks. Sylvian fissure initially appeared as a smooth surface and later underwent operculization to form obtuse and acute angulations with the adjacent temporal lobe by 20 and 24 weeks, respectively. Convexity sulci appeared later in gestation, beyond 25-26 weeks.ConclusionsUltrasonography, which is the commonest modality used in antenatal assessment of the fetus, can also be used to identify, familiarize, and provide a standard reference to assess normality of fetal sulcations. Neuronal migration disorders result in a wide spectrum of malformations of cortical development whose clinical manifestations include severe psychomotor retardation, developmental delays, motor deficits, seizures, and failure to thrive. Knowledge of normal development patterns of fetal cerebral sulci helps in early suspicion and detection of these cortical malformations, when present.

Pyridoxamine 5’-Phosphate Oxidase Deficiency: A Potentially Treatable Epileptic Encephalopathy

Pyridoxal phosphate-responsive neonatal epileptic encephalopathy due to pyridoxamine-5-primephosphate oxidase deficiency is a rare cause of epileptic encephalopathy. A neonate with this condition presents early in life with refractory seizures which does not respond to conventional anti-epileptic medications, depressed level of consciousness, and severe psychomotor retardation if left untreated. Early initiation of active cofactor pyridoxal-5’-phophate can be curative. We are describing a rare neurometabolic condition; the first case in the Kingdom of Bahrain to the best of our knowledge. Keywords: Pyridoxal-5’-phosphate, pyridoxamine 5’-phosphate oxidase, pyridoxine dependent epilepsy, epileptic encephalopathy, neonatal seizure

The eye - the window to the soul of the diagnosis: CHARGE Syndrome, a case report

The modality of inheritance in CHARGE syndrome is autosomal dominant, classically triggered by mutations in the chromo-domain helicase DNA binding protein-7 (CHD7) gene. CHARGE syndrome is characterized by the variable occurrence of coloboma, heart defects, atresia of the choanae, retarded growth and development, genital hypoplasia, ear anomalies and deafness. In this report, we describe an infant with a typical phenotype characterized by severe psychomotor retardation, facial asymmetry, coloboma, cortical blindness, unilateral choanal atresia, congenital heart anomalies, genital hypoplasia, cranial nerve IX/X dysfunction and global developmental delay that was diagnosed clinically. Following clinical diagnosis a complete sequencing of the CHD7 gene was carried out at the Institute for Medical Diagnostics GmbH in Ingelheim, Germany. Genomic DNA was screened for mutations in the CD7 gene (OMMIM 608892) on chromosome 8q12.1 The codon exon 2-38 and the respective exon-intron boundaries were amplified by polymerase chain reaction and analysed by direct sequencing. Resulting sequence data were compared with the reference sequence NM_017880.3 No mutation in CHD7 gene was detected as a genetic cause for the clinical phenotype of the patient. The MPLA multiplex ligation-dependent probe amplification analysis showed no copy number variation in the CHD7 gene. This case report underscores the importance of a detailed family history and physical examination in the diagnosis of CHARGE syndrome. Additionally, it provides valuable insight into the pathogenesis and clinical presentation of the syndrome as well as highlighting the benefits of a multidisciplinary approach. With supportive nurturing care, children with CHARGE syndrome can overcome the associated disabilities and develop necessary motor skills and a life-style enhancing level of fitness.

Psychiatric management of Patients in intensive care units.

Psychiatric management of Patients in intensive care units.

Canavan Disease - A Rare Case Report

Canavan disease is a rare autosomal recessive disorder characterized by progressive leukodystrophy involving white matter of the brain. Disease leads to severe psychomotor retardation, seizures and premature death. More prevalent among Jewish population. Among non-Jewish population incidence is approximately 1:100000. Prognosis is guarded with current management only symptomatic and supportive. There is no effective treatment, however early gene therapy has improved the quality of life of patients. Furthermore, Lithium citrate has also shown certain positive results in experimental models using rats. Even few human studies have also been done, however promising results require larger controlled trials. Keywords: MRI: Magnetic Resonance and Imaging, EEG: Electro Encephalogram, CD: Canavan Disease, ASPA: acetyl aspartate, LUCS: Lower Uterine Cesarean Section, OFC: Occipito Frontal Circumference, NAA: N-acetyl aspartate

Using Sensor Technology to Detect and Monitor Behavioral Symptoms of Dementia

Using Sensor Technology to Detect and Monitor Behavioral Symptoms of Dementia

Mortality outcomes and clinical background of children on maintenance dialysis without receiving kidney transplantation.

Some pediatric patients on maintenance dialysis may need end-of-life care in the future because of being excluded from the indication of kidney transplantation and experiencing difficulty in continuation of their dialysis. This study aimed to thoroughly elucidate mortality outcomes of children on maintenance dialysis including the cause of death and clinical background of exclusion from indication of transplantation. This single-center retrospective study enrolled 53 children who received kidney transplantation (5) or maintenance peritoneal dialysis (PD, 48) as initial renal replacement therapy (RRT). We examined the selected RRT modalities, mortality outcomes, clinical backgrounds of cause of death, and risk factors of excluding from future the indication of transplantation. Nine (17%) of all 53 patients, all receiving PD (9/48, 19%), were finally excluded from next RRT indication-7 were excluded due to severe extrarenal complications that indicated high risk for transplantation and 2 were excluded due to severe psychomotor retardation and at the guardians' discretion. Patients who were excluded from the indication had a younger age at PD induction and higher proportion of cerebral and cardiac complications or psychomotor retardation than patients who were included in the indication. Of the nine patients, seven died; of which, one patient died due to fatal progression of extrarenal complications and six died due to infectious or noninfectious dialysis-related complications. Patients with severe extrarenal complications or psychomotor retardation tend to be excluded from the indication of transplantation. Their condition becomes fatal because of the complications of long-term dialysis and progression in extrarenal complications.

Melancholic Features in Bipolar Depression and Response to Lamotrigine: A Pooled Analysis of Five Randomized Placebo-Controlled Trials.

A pilot study suggested lamotrigine may be more effective for bipolar depression with melancholic features. We tested this hypothesis in a pooled analysis of 5 randomized double-blind placebo-controlled trials of lamotrigine for acute bipolar depression. The pooled sample consisted of 1072 adult outpatients. Depressive symptoms were assessed for 7 to 10 weeks with the Hamilton Depression Rating Scale and the Montgomery-Åsberg Depression Rating Scale. The outcome measure was end-trial response (score reduction ≥ 50%). Melancholic features were assessed with both the Structured Clinical Interview for DSM-IV and baseline depression scale items, according to DSM criteria. The item-based melancholic specifier was associated with numerically larger treatment effects, although subgroup-treatment interactions in logistic regression models did not reach statistical significance. The small subgroup of patients with severe psychomotor retardation also appeared to benefit from lamotrigine. However, the Structured Clinical Interview for DSM-IV melancholic specifier was not associated with larger treatment effects. Baseline depression severity was inconsistently associated with response, depending on which scale was used to define severity. The 2 melancholia variables had poor agreement despite having similar prevalences. Our results do not clearly support the original hypothesis but do reinforce the importance of replicating secondary analyses of clinical trials with additional data.

GM1-gangliosidosis in a Nigerian infant: A case report

Gangliosidoses belong to the group of genetic lipid metabolism disorders, caused by defects of lysosome enzymes, inherited as an autosomal recessive trait. Gangliosidosis GM1 is caused by the deficiency of the acid beta-galactosidase (GLB11) resulting in the storage of the substrate- GM1 ganglioside in brain and visceral organs. GM1 gangliosidosis comprises three phenotypes, depending on the age of onset: an infantile, juvenile and adult type. In the infantile type dysmorphic features, severe psychomotor retardation, hepatosplenomegaly, bone changes and a cherry red spot in the macular region are seen. The juvenile GM1 gangliosidosis has no such external distinguishing features. In the adult type behavioural problems, dementia, extrapyramidal problems are specifically prominent. The authors present symptoms, clinical course and laboratory findings of a one-year-old boy with a diagnosed GM1 gangliosidosis. He presented with skin rashes since birth, delay in achievement of developmental milestones, progressive weight loss and recurrent diarrhoea of six-months duration.

Platelet Membrane Glycoprofiling in a PMM2-CDG Patient

Congenital disorders of glycosylation (CDG) are metabolic hereditary diseases caused by defects in the synthesis of glycoconjugates. CDG have been described in sugar-nucleotide biosynthesis and transporter, glycosyltransferases, vesicular transport, as well as in lipid biosynthesis and glycosylphosphatidylinositol anchors. PMM2-CDG is caused by mutations in the phosphomannomutase-2 (PMM2) gene and shows autosomal recessive inheritance. It affects all organs and tissues, ranging from severe psychomotor retardation to moderate intellectual disability. Alterations in the primary haemostatic system have been reported in these patients and they can lead to severe bleeding or excessive thrombosis with subsequent vascular insufficiency. Despite of being the most common CDG, platelet glycosylation and sialylation defects in PMM2-CDG patients remain incompletely characterized. In this study, we applied a lectin-based flow cytometry approach to report the first characterization of the highly glycosylated platelet membrane glycan profile in a PMM2-CDG patient. In the PMM2-CDG patient’s platelet samples, a decreased binding of SNA lectin, indicative of reduced terminal α-2-6 sialic acid content, and an increased binding of PNA lectin, suggesting desialylation of β-1-N-acetylgalactosamine residues, were observed. Reduced expression of terminal sialic acids in platelet membrane glycoproteins may contribute to the increased risk of hemorrhage reported in these patients by promoting platelet clearance and thrombocytopenia.