Autistic disorder and 22q11.2 duplication.

Although several reports have described the co-occurrence of autism in subjects with chromosome 22 abnormalities including trisomy 22, translocation 20/22, 22q11.2 deletion, ring chromosome 22, and 22q13.3 deletion, there is no report with 22q11.2 duplication. We report a 9-year-old girl, referred to our department for her behavioural problems and language delay. She was diagnosed with autistic disorder according to DSM-IV criteria. Because of her dysmorphic characteristics comprising narrow face, narrow forehead, mandibular prognathism, synophrys, and operated cleft palate and cardiac problems, she had gone under cytogenetic analysis. Although she was ascertained as suspected velocardiofacial syndrome (VCFS), the duplication of 22q11.2 was detected by interphase fluorescence in situ hybridization. Previous reports on the psychiatric aspects of 22q11.2 duplication have shown the existence of hyperactivity, learning disability, speech problems, and aggressive behaviours but not autism. Moreover, the lack of reports of co-occurrence of autism and 22q11.2 duplication may be related to paucity as a result of technical problems.     

Okamoto syndrome in a girl of Caucasian origin

We report the clinical and genetic evaluation of a 2‐year‐old Greek female with striking phenotypic similarities to the three previously published cases of Okamoto syndrome. The main features were characteristic facies, cleft palate, generalized hypotonia, severe developmental delay, congenital hydronephrosis, and congenital heart defects. Routine chromosome testing and whole‐genome high‐resolution comparative genetic hybridization analysis were negative for any gross numerical or structural chromosome aberrations and for microdeletions/duplications of more than 3 million base pairs respectively. Fluorescence in situ hybridization analysis for 22q11.2 deletion and DNA analysis of the protein tyrosine phosphatase, non‐receptor type II gene were normal, thus excluding DiGeorge and Noonan syndromes. Our patient did not show most of the cardinal features of Schinzel–Giedion, otopalatodigital, and C‐trigonocephaly syndromes. Moreover, in our patient some new malformations were identified: unilateral kidney hypoplasia and severe anal stenosis. The latter was considered as pertinent and is described here to establish a wider clinical spectrum of Okamoto syndrome. At the age of 3 years 6 months the child continues to show severe growth failure and significant global developmental delay. For the practising paediatrician it is prudent to bear Okamoto syndrome in mind, especially in children with learning disability and a pattern of dysmorphic features.     

Abnormal myelination in a patient with deletion 14q11.2q13.1

A male carrying an interstitial deletion of chromosome 14, presumably del(14)(q11.2q13), and presenting with abnormal myelination on magnetic resonance imaging is described. The abnormal myelination was evidenced as a high-signal intensity on T(2)-weighted magnetic resonance imaging. The patient had severe neurologic signs, various dysmorphic features, and a marked microcephaly. To our knowledge, this case is the first patient reported with abnormal myelination and a deletion of chromosome 14.     

Microduplication 22q11.2 in a child with autism spectrum disorder: clinical and genetic study

Microduplication of the 22q11.2 chromosomal region has been recognized since 1999 and has been associated with a highly variable phenotype. Neurodevelopmental impairment and behavioural problems are very common in patients with 22q11.2 duplication. Autism spectrum disorders (ASDs) have previously been reported in only two patients with 22q11.2 duplication and striking dysmorphic features. We report here on a 4‐year‐old male of healthy consanguineous parents presenting with ASD according to DSMIV, revised, criteria as a primary manifestation. The child walked at 16 months and started to say one word and some sounds. Parents noticed a subsequent developmental arrest. At 4 years his functional development age, evaluated by the Psychoeducational Profile, was roughly 6 months. Mild non‐specific facial dysmorphism was noted. Genetic analyses of the child demonstrated a de novo microduplication of the 22q11.2 chromosomal region. This genetic anomaly was best seen in interphases of blood lymphocytes and in buccal smear nuclei. Our case illustrates once again the clinical heterogeneity of the 22q11.2 duplication as well as the wide genetic complexity of ASD. We suggest that genetic evaluation of ASD should include fluorescence in‐situ hybridization analysis of the 22q11.2 chromosomal region.     

Microdeletion of chromosome 15q26.1 in a child with intractable generalized epilepsy

Chromosomal abnormalities involving deletions and duplications are known to cause severe developmental disorders, including mental retardation, dysmorphism, and seizures, in children. As the technique of array-based comparative genomic hybridization is being applied more frequently in the diagnostic evaluation of children with developmental disorders, novel pathologic chromosomal abnormalities are being identified. We report the case of a 9-year-old girl with a history of pervasive developmental disorder, growth delay, mild dysmorphic features, and intractable primary generalized epilepsy with a de novo microdeletion of approximately 0.73-0.94 Mb within chromosome 15q26.1. A much larger (5 Mb) but overlapping microdeletion has been previously reported in a 30-month-old child with similar phenotype including intractable myoclonic epilepsy, growth delay, and dysmorphic features. This leads us to propose that a potential candidate gene or genes within the deleted region involved in the pathogenesis of some forms of generalized intractable epilepsy, previously considered to be idiopathic.     

Autism in two females with duplications involving Xp11.22-p11.23

We present two phenotypically similar females with Xp duplication who have autism and epilepsy. Case 1 is a 14-year-old Honduran female with autism and medically refractory complex partial, secondarily generalized epilepsy. Case 2 is a 3-year-old Austrian female with autism and medically refractory complex partial epilepsy. Both patients also share features of severe intellectual disability (case 1 has a developmental quotient of 23, case 2 has a developmental quotient of 42) and dysmorphic facial features. Autism was confirmed by thorough clinical evaluations and testing. Case 1 has a karyotype of 46,X,dup(X)(p11.2-p22.33) and a highly skewed X-inactivation pattern (94:6). Brain magnetic resonance imaging (MRI) and electroencephalogram (EEG) were abnormal. Case 2 has a 5-megabase duplication of Xp11.22-p11.23 on chromosome microarray analysis. The patient has a random X-inactivation pattern (77:23). Brain MRI was normal, but EEG was abnormal. Both patients have duplications involving the Xp11.22-p11.23 region, indicating that this is an area of interest for future translational autism research.     

Duplication 15q14 --> pter: a rare chromosomal abnormality underlying bipolar affective disorder.

We have followed up a patient with 8q24.2 --> qter and 15q14 --> pter duplication due to a maternal reciprocal translocation, a condition related to Prader-Willi Syndrome. Apart from dysmorphic features, the patient suffered from recurring episodes of bipolar psychosis. Interestingly, PET scanning revealed revealed prominent bilateral hypometabolism in the frontal, temporal, and parietal lobes as well as in the cerebellum. Possible implications of this rare chromosomal abnormality with regards to psychiatric disorders are discussed, with emphasis on recent evidence suggesting chromosome 15q13-15 as a susceptibility locus for psychosis.     

Clinical and cytogenetic features of a Potocki–Lupski syndrome with the shortest 0.25 Mb microduplication in 17p11.2 including RAI1

Potocki–Lupski syndrome (PTLS [MIM 610883]) is a recently recognized microduplication syndrome associated with 17p11.2. It is characterized by mild facial dysmorphic features, hypermetropia, infantile hypotonia, failure to thrive, mental retardation, autistic spectrum disorders, behavioral abnormalities, sleep apnea, and cardiovascular anomalies. In several studies, the critical PTLS region was deduced to be 1.3 Mb in length, and included RAI1 and 17 other genes. We report a 3-year-old Korean boy with the smallest duplication in 17p11.2 and a milder phenotype. He had no family history of neurologic disease or developmental delay and no history of seizure, autistic features, or behavior problems. He showed subtle facial dysmorphic features (dolichocephaly and a mildly asymmetric smile) and flat feet. All laboratory tests were normal and he had no evidence of internal organ anomalies. He was found to have mild intellectual disabilities (full scale IQ 65 on K-WPPSI) and language developmental delay (age of 2.2 year-old on PRESS). Array comparative genomic hybridization (CGH) showed about a 0.25 Mb microduplication on chromosome 17p11.2 containing four Refseq (NCBI reference sequence) genes, including RAI1 [arr 17p11.2(17,575,978–17,824,623) × 3]. When compared with previously reported cases, the milder phenotype of our patient may be associated with the smallest duplication in 17p11.2, 0.25 Mb in length.     

Early developmental concerns in 22q11.2 deletion and duplication carriers

Background22q11.2 deletions (22qDEL) and duplications (22qDUP) are among the most common copy number variants (CNVs) associated with neurodevelopmental disorders (NDDs). Little is known about the earliest developmental features of 22q11.2 CNVs and whether developmental delays are detected in early childhood. This study primarily aimed to assess general development and social communication in 22q11.2 CNV carriers age 5 and under.MethodParticipants included parents of children age 5 and under with a reported genetic diagnosis of 22qDEL (N = 63) or 22qDUP (N = 30). In addition to questions addressing clinical and intervention information, two standardized parent questionnaires—the Ages & Stages Questionnaires, Third Edition (ASQ-3) and the Communication and Symbolic Behavior Scales Developmental Profile Infant/Toddler Checklist (ITC)—screened for developmental and social communication delays, respectively.ResultsDevelopmental delay and speech and/or language delay were the most commonly reported NDD diagnoses among young 22q11.2 CNV carriers, with prevalences at 19% and 17%, respectively. In the vast majority (91%) of 22q11.2 CNV carriers, parents reported concerns in at least one developmental domain, with 71% reporting global developmental concerns. 70% of parents of 22q11.2 CNV carriers age 2 and under also reported social communication concerns.ConclusionsThe high prevalence of reported developmental concerns in both CNV groups reinforces the need for close monitoring of early neurodevelopment in 22q11.2 CNV carriers with regard to both developmental delays and autism risk.     

Ring chromosome 14 with localization-related epilepsy: three cases

Three patients showing epileptic seizures and with mosaicism of ring chromosome 14 and monosomy for chromosome 14 are described. Patients were a 17-year-old boy, karyotype 46, XY, r(14)(p12q32.33)/45, XY, -14, a 7-month-old boy, karyotype 46, XY, r(14)(p11.2q32.33)/45, XY, -14, and a 10-month-old boy, karyotype 46, XY, r(14)(p12q32.31)/45, XY, -14. Microcephaly and alopecia were observed in the first patient. However, few dysmorphic features were found typical of ring 14 chromosome. He had exhibited complex partial seizures with secondary generalization at age 3 months and had mild motor and mental retardation. Both other patients had atonic seizures followed by staring, perioral cyanosis, and respiratory arrest at age 7 or 8 months. Both also showed mild developmental delay and had a few minor anomalies compatible with ring 14 chromosome. Interictal spikes were observed in the second patient in the right occipital region, whereas an interictal encephalogram of the third patient showed sporadic spikes in the left central region. In all three cases, seizures were resistant to common antiepileptic drugs.     

A case report of two male siblings with autism and duplication of Xq13–q21, a region including three genes predisposing for autism

Autism spectrum disorder, severe behaviour problems and duplication of the Xq12 to Xq13 region have recently been described in three male relatives. To describe the psychiatric comorbidity and dysmorphic features, including craniosynostosis, of two male siblings with autism and duplication of the Xq13 to Xq21 region, and attempt to narrow down the number of duplicated genes proposed to be leading to global developmental delay and autism. We performed DNA sequencing of certain exons of the TWIST1 gene, the FGFR2 gene and the FGFR3 gene. We also performed microarray analysis of the DNA. In addition to autism, the two male siblings exhibited severe learning disability, self-injurious behaviour, temper tantrums and hyperactivity, and had no communicative language. Chromosomal analyses were normal. Neither of the two siblings showed mutations of the sequenced exons known to produce craniosynostosis. The microarray analysis detected an extra copy of a region on the long arm of chromosome X, chromosome band Xq13.1–q21.1. Comparison of our two cases with previously described patients allowed us to identify three genes predisposing for autism in the duplicated chromosomal region. Sagittal craniosynostosis is also a new finding linked to the duplication.     

An emerging 1q21.1 deletion-associated neurodevelopmental phenotype

In this study, we describe the neurodevelopmental and epileptic phenotypes in a family with an inherited 1q21.1 deletion. During the pregnancy with the proband, increased nuchal translucency and oligohydramnion were detected. The proband showed mild global developmental delay and ataxic gait. Seizures started in the proband at the age of 2 years and manifested as generalized tonic-clonic seizures, atypical absence seizures, head drops, and drop attacks with no abnormal findings on interictal electroencephalogram. We performed an Agilent Human Genome CGH (comparative genomic hybridization) Microarray 105A, and a microdeletion on chromosome 1q21.1 was identified in both the patient and his asymptomatic father. This deletion encompasses 1.65 Mb and is larger than the reported recurrent class I deletions in this region. Cryptic cytogenetic abnormalities should be considered in patients with neurodevelopmental problems and atypical presentation of epilepsy with a normal electroencephalography (EEG).     

Atypical Prader-Willi syndrome with severe developmental delay and emaciation

A young boy showed features of Prader-Willi syndrome including hypotonia, cryptorchidism, a mildly dysmorphic facial appearance, a high-arched palate and an open triangular-shaped mouth, but had additional symptoms such as simian creases and multiple joint ankylosis in early infancy. Deletion of the long arm of chromosome 15(q11.2 to q13) was recognized. A muscle biopsy specimen showed variation in fiber size with hypertrophic type 1 fibers, type 2 fiber smallness, type 2B fiber paucity and an increased number of type 2C fibers. At the age of 4 1/2 years, he still showed severe developmental delay with severe muscle hypotonia, weakness and emaciation.     

Interstitial deletion of 14q, 46, XY, del (14) (q24.3q32.1) associated with status nonepileptic myoclonia and delayed myelination

A Japanese boy with interstitial deletion of the long arm of chromosome 14, including band 14q31, is described. The characteristic dysmorphic facial features, such as dolichocephaly, bushy eyebrows, horizontal narrow palpebral fissures, long philtrum, etc, and mental and motor developmental delay were observed. Other characteristic clinical manifestations were anuresis and status nonepileptic myoclonia The finding of delayed myelination of the cerebral white matter was observed on magnetic resonance examination, suggesting that an unknown factor related to myelination in the central nervous system might be localized in band 14q31.     

Duplication of the sodium channel gene cluster on 2q24 in children with early onset epilepsy

Purpose: Sodium channel gene aberrations are associated with a wide range of seizure disorders, particularly Dravet syndrome. They usually consist of missense or truncating gene mutations or deletions. Duplications involving multiple genes encoding for different sodium channels are not widely known. This article summarizes the clinical, radiologic, and genetic features of patients with 2q24 duplication involving the sodium channel gene cluster. Methods: A systematic review of the literature and report of two cases. Key Findings: Nine individuals with 2q24 duplication involving the sodium channel gene cluster are described (seven female, two male). All presented with severe seizures refractory to anticonvulsant drugs. Seizure onset was in the neonatal period in eight patients with SCN1A‐involvement, in infancy in one patient with SCN2A and SCN3A, but no SCN1A involvement. Seizure activity decreased and eventually stopped at 5–20 months of age. Seizures recurred at the age of 3 years in the patient with SCN2A and SCN3A, but no SCN1A involvement. Eight patients had a poor neurodevelopmental outcome despite seizure freedom. Significance: This article describes a distinct seizure disorder associated with a duplication of the sodium gene cluster on 2q24 described in otherwise healthy neonates and infants with severe, anticonvulsant refractory seizures and poor developmental outcome despite seizure freedom occurring at the age of 5–20 months.     

FBXO28 causes developmental and epileptic encephalopathy with profound intellectual disability

Chromosome 1q41‐q42 deletion syndrome is a rare cause of intellectual disability, seizures, dysmorphology, and multiple anomalies. Two genes in the 1q41‐q42 microdeletion, WDR26 and FBXO28, have been implicated in monogenic disease. Patients with WDR26 encephalopathy overlap clinically with those with 1q41‐q42 deletion syndrome, whereas only one patient with FBXO28 encephalopathy has been described. Seizures are a prominent feature of 1q41‐q42 deletion syndrome; therefore, we hypothesized that pathogenic FBXO28 variants cause developmental and epileptic encephalopathies (DEEs). We describe nine new patients with FBXO28 pathogenic variants (four missense, including one recurrent, three nonsense, and one frameshift) and analyze all 10 known cases to delineate the phenotypic spectrum. All patients had epilepsy and 9 of 10 had DEE, including infantile spasms (3) and a progressive myoclonic epilepsy (1). Median age at seizure onset was 22.5 months (range 8 months to 5 years). Nine of 10 patients had intellectual disability, which was profound in six of nine and severe in three of nine. Movement disorders occurred in eight of 10 patients, six of 10 had hypotonia, four of 10 had acquired microcephaly, and five of 10 had dysmorphic features, albeit different to those typically seen in 1q41‐q42 deletion syndrome and WDR26 encephalopathy. We distinguish FBXO28 encephalopathy from both of these disorders with more severe intellectual impairment, drug‐resistant epilepsy, and hyperkinetic movement disorders.     

Epilepsy,neuropsychiatric phenotypes,neuroimaging findings,and genotype-neurophenotype correlation in 22q11.2 deletion syndrome

Objectives:To describe the epilepsy, neuropsychiatric manifestations, and neuroimaging findings in a group of patients with 22q11.2 DS, and to correlate the size of the deleted genetic material with the severity of the phenotype.Methods:We retrospectively analyzed the medical records of 28 patients (21 pediatric patients and 7 adults) with a genetically confirmed diagnosis of 22q11.2 DS. Clinical data (epilepsy, neurological exam, neuropsychological and developmental assessment, and psychiatric disorders), neuroimaging, and cytogenetic tests were analyzed.Results:Of the 28 patients with 22q11.2 DS, 6 (21.4%) had epileptic seizures, 2 had symptomatic hypocalcemic seizures, 4 (14.2%) had a psychiatric disorder, which comprised of attention deficit hyperactivity disorder, autism spectrum disorder, psychosis, and mood disorder, and 17 (60.7%) had developmental delay. All patients with epilepsy had a developmental delay. Twelve patients underwent a neuropsychology assessment. Intellectual levels ranged from moderate intellectual disability (7/12, 58%) to average (5/12, 41.6%). Of the 16 patients, 6 (37.5%) had a normal brain, while 10 (62.5%) had abnormal neuroimaging findings. No significant correlation was found between the size of the deleted genetic material and the severity of the phenotype.Conclusion:22q11.2DS patients are at high risk to develop epilepsy, neuropsychiatric manifestations, and structural brain abnormalities. This indicates that this defined genetic locus is crucial for the development of the nervous system, and patients with 22q11.2 DS have genetic susceptibility to develop epilepsy.

22q11.2 deletion syndrome (22q11.2DS) has to many names such as velocardiofacial syndrome and DiGeorge syndrome, which is the most common microdeletion syndrome.1 It is due to hemizygous microdeletions on chromosome 22q11.2, it occurs 1 in 4000 live births, and 90% occur de novo. Most individuals with 22q11.2 DS lost about 3 Megabases (Mb) of DNA on chromosome 22 at position 22q11.2 in each cell.2 Some affected individuals have smaller deleted genetic material in this region. The clinical picture has a markedly different expression and incomplete penetrance. Therefore, 22q11.2DS has symptoms affecting several systems in the body, including congenital heart anomalies, palatal anomalies, hypocalcemia due to hypoplasia of parathyroid glands, immunodeficiency due to hypoplastic thymus, facial dysmorphism, disorders of cognition and behavior, and psychiatric disorders.3 However, few studies have been conducted on the epilepsy, neurological, neuroimaging, and neuropsychiatric features of 22q11.2 DS.This study aimed to examine the epilepsy, neurological, neuropsychiatric phenotypes, and neuroimaging findings in a series of individuals with 22q11.2 DS and to correlate the genotype with the neurophenotype.     

15q11.2 BP1-BP2 microdeletion presenting as progressive spastic paraplegia and brain images of small vessel disease

15q11.2 BP1-BP2 microdeletion is related to clinical abnormalities including general developmental delay, speech and neuropsychiatric disorders, which is known as Angelman syndrome. However, the clinical penetrance and phenotype of 15q11.2 BP1-BP2 deletion is varied and confusing. Herein, we retrospectively described a 50-year-old male patient who manifested with progressive spastic paraplegia of lower limbs and episodic exacerbation. While brain MRI showed white matter hyperintensities, lacunes, cerebral microbleeds, enlarged perivascular spaces, and brain atrophy, mimicking small vessel disease. Next-generation sequencing combining multiplex ligation-dependent probe amplification identified a 253 kb 15q11.2 BP1-BP2 microdeletion, encompassing 4 conserved imprinted genes (NIPA1, NIPA2, CYFIP1 and TUBGCP5). This report will build new connections among spastic paraplegia, small vessel disease and 15q11.2 BP1-BP2 microdeletion.

15q11.2 BP1–BP2 (OMIM 615656) microdeletion refers to the deletion between breakpoint 1 (BP1) and breakpoint 2 (BP2) compassing 4 evolutionarily conserved nonimprinted genes (NIPA1, NIPA2, CYFIP1, and TUBGCP5) in the q-arm of chromosome 15. This deletion is clinically presented as Prader-Willi syndrome or Angelman syndrome (AS). ¹ In 2007, Murthy et al ² first reported AS in a 3.5-year-old boy due to a 253-kb microdeletion in 15q11.2 BP1-BP2, who presented with mental retardation, developmental delay, speech delay, and neurological disorders. Subsequently, the clinical spectrum of the 15q11.2 BP1-BP2 deletion has been expanded to neuropsychiatric disorders, autism spectrum disorders, epilepsy, general dysmorphic features, and so forth. ^2,3 But the presentation of progressive spastic paraplegia and small vessel disease has not been reported.Cerebral small-vessel disease (CSVD) is a group of diseases based on brain imaging biomarkers, including recent small subcortical infarcts, white matter hyperintensities, lacunes, cerebral microbleeds, enlarged perivascular spaces, and brain atrophy. ⁴ Patients present with recurrent stroke syndromes, cognitive impairments, gait dysfunction, and a general decline in function. ⁵ Single-gene disorders are rare but an important cause for CSVD, including cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy caused by a mutation in the NOTCH3 gene, Fabry disease caused by the GLA gene, and so forth. ⁵ This study aimed to report a case who presented with progressive spastic paraplegia, while the brain magnetic resonance imaging (MRI) revealed typical features of small-vessel disease. The genetic analysis identified 253-kb microdeletion in 15q11.2 BP1-BP2. The findings of this report may expand the phenotypic spectrum of 15q11.2 BP1-BP2 microdeletion.     

Epilepsy and Other Neuropsychiatric Manifestations in Children and Adolescents with 22q11.2 Deletion Syndrome

MethodsWe retrospectively analyzed the medical records of 145 child and adolescent patients (72 males and 73 females) with genetically diagnosed 22q11.2DS. The clinical data included seizures, growth chart, psychological reports, development characteristics, school performance, other clinical manifestations, and laboratory findings.ResultsOf the 145 patients with 22q11.2DS, 22 (15.2%) had epileptic seizures, 15 (10.3%) had developmental delay, and 5 (3.4%) had a psychiatric illness. Twelve patients with epilepsy were classified as genetic epilepsy whereas the remaining were classified as structural, including three with malformations of cortical development. Patients with epilepsy were more likely to display developmental delay (odds ratio=3.98; 95% confidence interval=1.5-10.5; p=0.005), and developmental delay was more common in patients with structural epilepsy than in those with genetic epilepsy.ConclusionsPatients with 22q11.2DS have a high risk of epilepsy, which in these cases is closely related to other NP manifestations. This implies that this specific genetic locus is critically linked to neurodevelopment and epileptogenesis.