Apparent germline mosaicism for a novel 19p13.13 deletion disrupting NFIX and CACNA1A

Natural history in Malan syndrome: survey of 28 adults and literature review

BACKGROUND

Malan syndrome (MALNS), previously referred to as "Sotos syndrome 2" due to its resemblance to Sotos syndrome (SS), is an ultra-rare neurodevelopmental disorder characterized by overgrowth, typical craniofacial features, intellectual disability (ID), and a range of psychobehavioral, musculoskeletal, vision and neurological signs. As MALNS and SS partly overlap, it is essential to more accurately profile their clinical presentations and highlight their differences in order to improve syndrome specific management. An increasing number of individuals with MALNS reach adult-age though the natural history of the disorder is poorly characterized due to the small number of adult individuals described so far. As a consequence, current guidelines are limited to the pediatric population. Further delineation of MALNS is essential to optimize care in adulthood.

RESULTS

A mixed approach based on cross-sectional data collection with a survey disseminated to caregivers of adults with molecularly confirmed MALNS and literature review was conducted. Twenty-eight caregivers completed the survey. Clinical presentation in adulthood is multisystemic and defined by psychobehavioral comorbidities (96%), musculoskeletal involvement (96%), vision impairment (96%) and neurological complications (86%). The most common signs were anxiety (79%), hypotonia (75%), movement difficulty (75%), scoliosis (64%), problems with coordination (61%), strabismus (57%), constipation (54%), breastbone abnormalities (54%) and advanced bone age during childhood (54%). Impaired vision was complicated by vision decline (36%) and optic atrophy (32%). We report some previously unidentified features, including high pain threshold (46%), incontinence (25%), tremors (21%), muscle hypoplasia (18%) and tics (18%).

CONCLUSIONS

This survey in the adult population has allowed a more complete description of the natural history of MALNS. Our findings will contribute to the development and improvement of standards of care for adults with MALNS to assure optimal health monitoring and treatment of evolutive complications. We propose additional recommendations to the previous dataset of clinical evaluations specifically applied to adults. The comparison of MALNS and SS adult presentation highlights significant differences in terms of prevalence and severity of ID, behavioral issues, and vision problems, confirming that a proper differential diagnosis between the two conditions is indispensable to guide physicians and mental health professionals to syndrome specific management.

Arterial aneurysm and dissection: toward the evolving phenotype of Tatton-Brown-Rahman syndrome

BACKGROUND

Tatton-Brown-Rahman syndrome (TBRS) is a rare disorder, caused by DNMT3A heterozygous pathogenic variants, and first described in 2014. TBRS is characterised by overgrowth, intellectual disability, facial dysmorphism, hypotonia and musculoskeletal features, as well as neurological and psychiatric features. Cardiac manifestations have also been reported, mainly congenital malformations such as atrial septal defect, ventricular septal defect and cardiac valvular disease. Aortic dilatation has rarely been described.

METHODS

Here we have undertaken a detailed clinical and molecular description of eight previously unreported individuals, who had TBRS and arterial dilatation and/or dissection, mainly thoracic aortic aneurysm (TAA). We have also reviewed the seven previously published cases of TAA in individuals with TBRS to try to better delineate the vascular phenotype and to determine specific follow-up for this condition.

RESULTS

We include eight new patients with TBRS who presented with arterial aneurysms mainly involving aorta. Three of these patients presented with dissection that required critical surgery.

CONCLUSIONS

Arterial aneurysms and dissections are a potentially lethal, age-dependent manifestation. The prevalence of aortic disease in individuals with TBRS is far in excess of that expected in the general population. This cohort, together with individuals previously published, illustrates the importance to consider dilatation/dissection, mainly in aorta but also in other arteries. Arterial vascular weakness may therefore also be a cardinal feature of TBRS and vascular surveillance is recommended.

Case Report: Novel pathogenic variant in NFIX in two sisters with Malan syndrome due to germline mosaicism

Malan syndrome is an autosomal dominant disorder caused by pathogenic variants in NFIX with less than 100 cases reported thus far. NFIX is important for stem cell proliferation, quiescence, and differentiation during development and its protein plays a role in replication, signal transduction, and transcription. As a result of pathogenic variants, symptoms of Malan syndrome include overgrowth, intellectual disability, speech delay, and dysmorphic features. Currently, the recurrence risk for this disorder is indicated at less than 1%, standard for de novo autosomal dominant disorders. Herein, we report an additional set of sisters with the same novel pathogenic variant in NFIX and clinical features consistent with Malan syndrome providing evidence of germline mosaicism. Considering the rarity of this condition in conjunction with three previous reports of germline mosaicism, it is worthwhile to investigate and re-evaluate the proper recurrence risk for this condition. This discovery would be paramount for family planning and genetic counseling practices in families with affected individuals.

Characterization of Cognitive, Language and Adaptive Profiles of Children and Adolescents with Malan Syndrome

Malan Syndrome (MS) is an ultra-rare overgrowth genetic syndrome due to heterozygous variants or deletions in the Nuclear Factor I X (NFIX) gene. It is characterized by an unusual facial phenotype, generalized overgrowth, intellectual disability (ID) and behavioral problems. Even though limitations in cognitive and adaptive functioning have been previously described, systematic studies on MS cohorts are still lacking. Here, we aim to define the cognitive and adaptive behavior profile of MS children and adolescents, providing quantitative data from standardized evaluations. Subjects included in this study were evaluated from October 2020 to January 2022 and the study is based on a retrospective data archive: fifteen MS individuals were recruited and underwent evaluation with Wechsler Intelligence Scales, Leiter International Performance Scales and Griffith Mental Development Scales for cognitive profiles and with Vineland Adaptive Behavior Scales-II Edition (VABS-II) for adaptive functioning. Language skills and visuomotor integration abilities were assessed too. Comparisons and correlations between scales and subtests were performed. All the assessed MS individuals showed both low cognitive and adaptive functioning. One subject presented with mild ID, five had moderate ID and eight showed severe ID. One female toddler received a diagnosis of psychomotor delay. Linguistic skills were impaired in all individuals, with language comprehension relatively more preserved. Results revealed significant differences between VABS-II subdomains and a strong relationship between cognitive and adaptive functioning. All subjects exhibited mild to moderate ID and adaptive behavior lower than normal, with communication skills being the most affected. Regarding the daily living skills domain, personal and community subscale scores were dramatically lower than for the domestic subdomain, highlighting the importance of considering behavior within developmental and environmental contexts. Our cognitive and adaptive MS characterization provides a more accurate quantitative MS profiling, which is expected to help clinicians to better understand the complexity of this rare disorder.

A deep phenotyping experience: up to date in management and diagnosis of Malan syndrome in a single center surveillance report

Background

Malan syndrome (MALNS) is a recently described ultrarare syndrome lacking guidelines for diagnosis, management and monitoring of evolutive complications. Less than 90 patients are reported in the literature and limited clinical information are available to assure a proper health surveillance.

Results

A multidisciplinary team with high expertise in MALNS has been launched at the “Ospedale Pediatrico Bambino Gesù”, Rome, Italy. Sixteen Italian MALNS individuals with molecular confirmed clinical diagnosis of MALNS were enrolled in the program. For all patients, 1-year surveillance in a dedicated outpatient Clinic was attained. The expert panel group enrolled 16 patients and performed a deep phenotyping analysis directed to clinically profiling the disorder and performing critical revision of previously reported individuals. Some evolutive complications were also assessed. Previously unappreciated features (e.g., high risk of bone fractures in childhood, neurological/neurovegetative symptoms, noise sensitivity and Chiari malformation type 1) requiring active surveillance were identified. A second case of neoplasm was recorded. No major cardiovascular anomalies were noticed. An accurate clinical description of 9 new MALNS cases was provided.

Conclusions

Deep phenotyping has provided a more accurate characterization of the main clinical features of MALNS and allows broadening the spectrum of disease. A minimal dataset of clinical evaluations and follow-up timeline has been proposed for proper management of patients affected by this ultrarare disorder.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02384-9.

Aortic root dilatation and dilated cardiomyopathy in an adult with Tatton-Brown-Rahman syndrome

Tatton-Brown-Rahman syndrome is an autosomal dominant overgrowth syndrome caused by pathogenic DNMT3A variants in the germline. Clinical findings of tall stature due to postnatal overgrowth, intellectual disability, and characteristic facial features, are the most consistent findings observed in patients with Tatton-Brown-Rahman syndrome (TBRS). Since the syndrome was first described in 2014, an expanding spectrum of neuropsychiatric, musculoskeletal, neurological, and cardiovascular manifestations have been reported. However, most TBRS cases described in the literature are children with de novo DNMT3A variants, signaling a need to better characterize the phenotypes in adults. In this report, we describe a 34 year old referred to genetics for possible Marfan syndrome with aortic root dilatation, mitral valve prolapse, and dilated cardiomyopathy, who was diagnosed with TBRS due to a heterozygous de novo DNMT3A variant. This represents the third reported TBRS case with aortic root dilation and the second with cardiomyopathy. Collectively, these data provide evidence for an association with aortic disease and cardiomyopathy, highlight the clinical overlap with Marfan syndrome, and suggest that cardiovascular surveillance into adulthood is indicated.

Lyl-1 regulates primitive macrophages and microglia development

During ontogeny, macrophage populations emerge in the Yolk Sac (YS) via two distinct progenitor waves, prior to hematopoietic stem cell development. Macrophage progenitors from the primitive/"early EMP" and transient-definitive/"late EMP" waves both contribute to various resident primitive macrophage populations in the developing embryonic organs. Identifying factors that modulates early stages of macrophage progenitor development may lead to a better understanding of defective function of specific resident macrophage subsets. Here we show that YS primitive macrophage progenitors express Lyl-1, a bHLH transcription factor related to SCL/Tal-1. Transcriptomic analysis of YS macrophage progenitors indicate that primitive macrophage progenitors present at embryonic day 9 are clearly distinct from those present at later stages. Disruption of Lyl-1 basic helix-loop-helix domain leads initially to an increased emergence of primitive macrophage progenitors, and later to their defective differentiation. These defects are associated with a disrupted expression of gene sets related to embryonic patterning and neurodevelopment. Lyl-1-deficiency also induce a reduced production of mature macrophages/microglia in the early brain, as well as a transient reduction of the microglia pool at midgestation and in the newborn. We thus identify Lyl-1 as a critical regulator of primitive macrophages and microglia development, which disruption may impair resident-macrophage function during organogenesis.

From Genotype to Phenotype: Expanding the Clinical Spectrum of CACNA1A Variants in the Era of Next Generation Sequencing

Ion channel dysfunction is a key pathological substrate of episodic neurological disorders. A classical gene associated to paroxysmal movement disorders is CACNA1A, which codes for the pore-forming subunit of the neuronal calcium channel P/Q. Non-polyglutamine CACNA1A variants underlie familial hemiplegic ataxia type 1 (FHM1) and episodic ataxia type 2 (EA2). Classical paroxysmal manifestations of FHM1 are migraine attacks preceded by motor aura consisting of hemiparesis, aphasia, and disturbances of consciousness until coma. Patients with EA2 suffer of recurrent episodes of vertigo, unbalance, diplopia, and vomiting. Beyond these typical presentations, several reports highlighted manifold clinical features associated with P/Q channelopathies, from chronic progressive cerebellar ataxia to epilepsy and psychiatric disturbances. These manifestations may often outlast the burden of classical episodic symptoms leading to pitfalls in the diagnostic work-up. Lately, the spreading of next generation sequencing techniques linked de novo CACNA1A variants to an even broader phenotypic spectrum including early developmental delay, autism spectrum disorders, epileptic encephalopathy, and early onset paroxysmal dystonia. The age-dependency represents a striking new aspect of these phenotypes und highlights a pivotal role for P/Q channels in the development of the central nervous system in a defined time window. While several reviews addressed the clinical presentation and treatment of FHM1 and EA2, an overview of the newly described age-dependent manifestations is lacking. In this Mini-Review we present a clinical update, delineate genotype-phenotype correlations as well as summarize evidence on the pathophysiological mechanisms underlying the expanded phenotype associated with CACNA1A variants.

Pathogenic variant in NFIX gene affecting three sisters due to paternal mosaicism

We present a family with three girls presenting similar dysmorphic features, including overgrowth, intellectual disability, macrocephaly, prominent forehead, midface retrusion, strabismus, and scoliosis. Both parents were unaffected, suggesting the presence of an autosomal recessive syndrome. Following exome sequencing, a heterozygous nonsense variant was identified in the NFIX gene in all three siblings. The father appeared to have a low-grade (7%) mosaicism for this variant in his blood. Previously, de novo pathogenic variants in NFIX have been identified in Marshall-Smith syndrome and Malan syndrome, which share distinctive phenotypic features shared with the patients of the present family. This case emphasizes the importance of further molecular analysis especially in familial cases, to exclude the possibility of parental mosaicism.

Episodic Ataxias: Faux or Real?

The term Episodic Ataxias (EA) was originally used for a few autosomal dominant diseases, characterized by attacks of cerebellar dysfunction of variable duration and frequency, often accompanied by other ictal and interictal signs. The original group subsequently grew to include other very rare EAs, frequently reported in single families, for some of which no responsible gene was found. The clinical spectrum of these diseases has been enormously amplified over time. In addition, episodes of ataxia have been described as phenotypic variants in the context of several different disorders. The whole group is somewhat confused, since a strong evidence linking the mutation to a given phenotype has not always been established. In this review we will collect and examine all instances of ataxia episodes reported so far, emphasizing those for which the pathophysiology and the clinical spectrum is best defined.

Malan syndrome in a patient with 19p13.2p13.12 deletion encompassing NFIX and CACNA1A genes: Case report and review of the literature

Background

Malan syndrome is a recently introduced overgrowth disorder described in a limited number of individuals. Haploinsufficiency and also point mutations of NFIX gene have been proposed as its leading causative mechanism, however, due to the limited number of cases and different deletion sizes, genotype/phenotype correlations are still limited.

Methods

Here, we report the first Brazilian case of Malan syndrome caused by a 990 kb deletion in 19p13.2p13.12, focusing on clinical and behavioral aspects of the syndrome.

Results

The patient presented with macrocephaly, facial dysmorphisms, hypotonia, developmental delay, moderate thoracolumbar scoliosis, and seizures. The intellectual and behavioral assessments showed severe cognitive, language, and adaptive functions impairments. The 19p deleted region of our patient encompasses NFIX, CACNA1A, which seems to be related to a higher frequency of seizures among individuals with microdeletions in 19p13.2, and 15 other coding genes, including CC2D1A and NACC1, both known to be involved in neurobiological process and pathways.

Conclusion

Deletions involving NFIX gene should be considered in patients with overgrowth during childhood, macrocephaly, developmental delay, and seizures, as well as severe intellectual disability.

The neuropsychiatric phenotype in CACNA1A mutations: a retrospective single center study and review of the literature

BACKGROUND AND PURPOSE

CACNA1A encodes the α1 subunit of the neuronal calcium channel P/Q. CACNA1A mutations underlie three allelic disorders: familial hemiplegic migraine type 1 (FHM1), episodic ataxia type 2 (EA2) and spinocerebellar ataxia type 6 (SCA6). A clear-cut genotype-phenotype correlation is often lacking since clinical manifestations may overlap. Several case reports have described cognitive and behavioral features in CACNA1A disorders, but studies in larger case series are lacking.

METHODS

Genetically confirmed CACNA1A cases were retrieved from the database of the ataxia outpatient clinic of the Department of Neurology at Innsbruck Medical University. Clinical charts and neuropsychological test results were retrospectively analyzed. In addition, a review of the literature including only genetically confirmed cases was performed.

RESULTS

Forty-four CACNA1A cases were identified in our database. Delayed psychomotor milestones and poor school performance were described in seven (four FHM1, three EA2) and eight (three FHM1, five EA2) patients, respectively. Psychiatric comorbidities were diagnosed in eight patients (two FHM1, six EA2). Neuropsychological testing was available for 23 patients (11 FHM1, 10 EA2, two SCA6). Various cognitive deficits were documented in 21 cases (all patients except one SCA6). Impairments were predominantly seen in figural memory, visuoconstructive abilities and verbal fluency. In the literature, an early psychomotor delay is described in several children with EA2 and FHM1, whilst reports of cognitive and psychiatric findings from adult cases are scarce.

CONCLUSIONS

Neuropsychiatric manifestations are common in episodic CACNA1A disorders. In the case of otherwise unexplained developmental delay and a positive family history, CACNA1A mutations should be considered in the differential diagnosis.

Further delineation of Malan syndrome

Malan syndrome is an overgrowth disorder described in a limited number of individuals. We aim to delineate the entity by studying a large group of affected individuals. We gathered data on 45 affected individuals with a molecularly confirmed diagnosis through an international collaboration and compared data to the 35 previously reported individuals. Results indicate that height is > 2 SDS in infancy and childhood but in only half of affected adults. Cardinal facial characteristics include long, triangular face, macrocephaly, prominent forehead, everted lower lip, and prominent chin. Intellectual disability is universally present, behaviorally anxiety is characteristic. Malan syndrome is caused by deletions or point mutations of NFIX clustered mostly in exon 2. There is no genotype‐phenotype correlation except for an increased risk for epilepsy with 19p13.2 microdeletions. Variants arose de novo, except in one family in which mother was mosaic. Variants causing Malan and Marshall‐Smith syndrome can be discerned by differences in the site of stop codon formation. We conclude that Malan syndrome has a well recognizable phenotype that usually can be discerned easily from Marshall–Smith syndrome but rarely there is some overlap. Differentiation from Sotos and Weaver syndrome can be made by clinical evaluation only.

19p13 microduplications encompassing NFIX are responsible for intellectual disability, short stature and small head circumference

Syndromes caused by copy number variations are described as reciprocal when they result from deletions or duplications of the same chromosomal region. When comparing the phenotypes of these syndromes, various clinical features could be described as reversed, probably due to the opposite effect of these imbalances on the expression of genes located at this locus. The NFIX gene codes for a transcription factor implicated in neurogenesis and chondrocyte differentiation. Microdeletions and loss of function variants of NFIX are responsible for Sotos syndrome-2 (also described as Malan syndrome), a syndromic form of intellectual disability associated with overgrowth and macrocephaly. Here, we report a cohort of nine patients harboring microduplications encompassing NFIX. These patients exhibit variable intellectual disability, short stature and small head circumference, which can be described as a reversed Sotos syndrome-2 phenotype. Strikingly, such a reversed phenotype has already been described in patients harboring microduplications encompassing NSD1, the gene whose deletions and loss-of-function variants are responsible for classical Sotos syndrome. Even though the type/contre-type concept has been criticized, this model seems to give a plausible explanation for the pathogenicity of 19p13 microduplications, and the common phenotype observed in our cohort.

A novel mutation of NFIX causes Sotos-like syndrome (Malan syndrome) complicated with thoracic aortic aneurysm and dissection

Malan syndrome has recently been characterized to present Sotos-like phenotypes, such as intellectual disability and macrocephaly, with mutations in the NFIX gene. Herein, we report a 38-year-old patient with a novel single adenine insertion mutation in exon 2 of the NFIX gene (c.290_291insA). He developed early-onset thoracic aortic aneurysm and dissection, which was a rare complication but deserves particular attention in relatively long-lived patients with Sotos-like phenotypes.

A Recurrent De Novo Variant in NACC1 Causes a Syndrome Characterized by Infantile Epilepsy, Cataracts, and Profound Developmental Delay

Whole-exome sequencing (WES) has increasingly enabled new pathogenic gene variant identification for undiagnosed neurodevelopmental disorders and provided insights into both gene function and disease biology. Here, we describe seven children with a neurodevelopmental disorder characterized by microcephaly, profound developmental delays and/or intellectual disability, cataracts, severe epilepsy including infantile spasms, irritability, failure to thrive, and stereotypic hand movements. Brain imaging in these individuals reveals delay in myelination and cerebral atrophy. We observe an identical recurrent de novo heterozygous c.892C>T (p.Arg298Trp) variant in the nucleus accumbens associated 1 (NACC1) gene in seven affected individuals. One of the seven individuals is mosaic for this variant. NACC1 encodes a transcriptional repressor implicated in gene expression and has not previously been associated with germline disorders. The probability of finding the same missense NACC1 variant by chance in 7 out of 17,228 individuals who underwent WES for diagnoses of neurodevelopmental phenotypes is extremely small and achieves genome-wide significance (p = 1.25 × 10-14). Selective constraint against missense variants in NACC1 makes this excess of an identical missense variant in all seven individuals more remarkable. Our findings are consistent with a germline recurrent mutational hotspot associated with an allele-specific neurodevelopmental phenotype in NACC1.

Intellectual disability and overgrowth-A new case of 19p13.13 microdeletion syndrome with digital abnormalities

19p13.13 microdeletion has been consistently associated with intellectual disability, overgrowth, and macrocephaly. We report a 19p13.13 microdeletion, detected by array CGH, in a girl with moderate intellectual disability, overgrowth with macrocephaly, prominent digit pads and deep digital creases, hypotonia, ataxia, and strabismus. This clinical report helps to delineate the role of some of the deleted genes, as well as the phenotype of recently described 19p13.13 microdeletion syndrome, including the description of novel digital abnormalities.

CACNA1A haploinsufficiency causes cognitive impairment, autism and epileptic encephalopathy with mild cerebellar symptoms

CACNA1A loss-of-function mutations classically present as episodic ataxia type 2 (EA2), with brief episodes of ataxia and nystagmus, or with progressive spinocerebellar ataxia (SCA6). A minority of patients carrying CACNA1A mutations develops epilepsy. Non-motor symptoms associated with these mutations are often overlooked. In this study, we report 16 affected individuals from four unrelated families presenting with a spectrum of cognitive impairment including intellectual deficiency, executive dysfunction, ADHD and/or autism, as well as childhood-onset epileptic encephalopathy with refractory absence epilepsy, febrile seizures, downbeat nystagmus and episodic ataxia. Sequencing revealed one CACNA1A gene deletion, two deleterious CACNA1A point mutations including one known stop-gain and one new frameshift variant and a new splice-site variant. This report illustrates the phenotypic heterogeneity of CACNA1A loss-of-function mutations and stresses the cognitive and epileptic manifestations caused by the loss of CaV2.1 channels function, presumably affecting cerebellar, cortical and limbic networks.

Cryptic FMR1 mosaic deletion in a phenotypically normal mother of a boy with fragile X syndrome: case report

BACKGROUND

Increasing number of case reports of mosaic mutations and deletions have better armed clinicians and geneticists with more accurate and focused prenatal diagnoses. Since mosaicism means a significant increase of recurrence risk, detailed parental profiling is essential for risk assessments.

CASE PRESENTATION

We here describe a clinically unaffected mother with a son who had fragile X syndrome (FXS) caused by a large deletion that includes the entire FMR1. To assess the recurrence risk regarding her second pregnancy, a series of genetic tests were conducted to establish this mother's status. Routine single nucleotide polymorphism (SNP) array and fluorescence in situ hybridisation (FISH) analyses detected two normal FMR1 copies in her blood. However, in-depth studies across the deleted region revealed varying proportions of mosaic deletion in her somatic tissues: lowest in the blood, moderately higher in the skin, urine sediment and menstrual discharge and highest in her eyebrow. Further FISH analysis of her skin-derived fibroblasts confirmed mosaicism of 13%.

CONCLUSION

To our knowledge, this is the first characterized case of a female who was mosaic for an FMR1 deletion and extensive investigation of her mosaic status provided valuable information for her reproduction choices. Our case report may also alert clinicians and geneticists that a cryptic mosaicism with somatic heterogeneity should be carefully considered in families with children having clinically defined 'de novo' mutations, to avoid a second pregnancy with identical genetic abnormalities.

Malan syndrome: Sotos-like overgrowth with de novo NFIX sequence variants and deletions in six new patients and a review of the literature

De novo monoallelic variants in NFIX cause two distinct syndromes. Whole gene deletions, nonsense variants and missense variants affecting the DNA-binding domain have been seen in association with a Sotos-like phenotype that we propose is referred to as Malan syndrome. Frameshift and splice-site variants thought to avoid nonsense-mediated RNA decay have been seen in Marshall-Smith syndrome. We report six additional patients with Malan syndrome and de novo NFIX deletions or sequence variants and review the 20 patients now reported. The phenotype is characterised by moderate postnatal overgrowth and macrocephaly. Median height and head circumference in childhood are 2.0 and 2.3 standard deviations (SD) above the mean, respectively. There is overlap of the facial phenotype with NSD1-positive Sotos syndrome in some cases including a prominent forehead, high anterior hairline, downslanting palpebral fissures and prominent chin. Neonatal feeding difficulties and/or hypotonia have been reported in 30% of patients. Developmental delay/learning disability have been reported in all cases and are typically moderate. Ocular phenotypes are common, including strabismus (65%), nystagmus (25% ) and optic disc pallor/hypoplasia (25%). Other recurrent features include pectus excavatum (40%) and scoliosis (25%). Eight reported patients have a deletion also encompassing CACNA1A, haploinsufficiency of which causes episodic ataxia type 2 or familial hemiplegic migraine. One previous case had episodic ataxia and one case we report has had cyclical vomiting responsive to pizotifen. In individuals with this contiguous gene deletion syndrome, awareness of possible later neurological manifestations is important, although their penetrance is not yet clear.