Microdeletion 1p32p31 Presenting with Moyamoya Disease and Incomplete Hippocampal Inversion.

Background: The chromosome 1p32p31 deletion syndrome is a contiguous gene disorder with a variable phenotype characterized by brain malformations with or without urinary tract defects, besides neurodevelopmental delay and dysmorphisms. An expanded phenotype was proposed based on additional findings, including one previous report of a patient presenting with moyamoya disease. Case Presentation: The authors report a patient presenting with early neurodevelopmental delay, hydrocephalus, renal malformation, and dysmorphisms. After presenting with a sudden choreic movement disorder, the neuroimaging investigation revealed an ischemic stroke, moyamoya disease, and bilateral incomplete hippocampal inversion. Chromosomal microarray analysis revealed a deletion of 13.2 Mb at 1p31.3p32.2, compatible with the contiguous gene syndrome caused by microdeletions of this region. Discussion/Conclusion: This is the second report of a patient who developed Moyamoya disease and the first to describe bilateral incomplete hippocampal inversion in this microdeletion syndrome.

Low-pass whole genome sequencing as a cost-effective alternative to chromosomal microarray analysis for low- and middle-income countries.

Low-pass whole genome sequencing (LP-WGS) has been applied as alternative method to detect copy number variants (CNVs) in the clinical setting. Compared with chromosomal microarray analysis (CMA), the sequencing-based approach provides a similar resolution of CNV detection at a lower cost. In this study, we assessed the efficiency and reliability of LP-WGS as a more affordable alternative to CMA. A total of 1363 patients with unexplained neurodevelopmental delay/intellectual disability, autism spectrum disorders, and/or multiple congenital anomalies were enrolled. Those patients were referred from 15 nonprofit organizations and university centers located in different states in Brazil. The analysis of LP-WGS at 1x coverage (>50kb) revealed a positive testing result in 22% of the cases (304/1363), in which 219 and 85 correspond to pathogenic/likely pathogenic (P/LP) CNVs and variants of uncertain significance (VUS), respectively. The 16% (219/1363) diagnostic yield observed in our cohort is comparable to the 15%-20% reported for CMA in the literature. The use of commercial software, as demonstrated in this study, simplifies the implementation of the test in clinical settings. Particularly for countries like Brazil, where the cost of CMA presents a substantial barrier to most of the population, LP-WGS emerges as a cost-effective alternative for investigating copy number changes in cytogenetics.

Genome Sequencing in an Individual Presenting with 22q11.2 Deletion Syndrome and Juvenile Idiopathic Arthritis.

Juvenile idiopathic arthritis is a heterogeneous group of diseases characterized by arthritis with poorly known causes, including monogenic disorders and multifactorial etiology. 22q11.2 proximal deletion syndrome is a multisystemic disease with over 180 manifestations already described. In this report, the authors describe a patient presenting with a short stature, neurodevelopmental delay, and dysmorphisms, who had an episode of polyarticular arthritis at the age of three years and eight months, resulting in severe joint limitations, and was later diagnosed with 22q11.2 deletion syndrome. Investigation through Whole Genome Sequencing revealed that he had no pathogenic or likely-pathogenic variants in both alleles of the MIF gene or in genes associated with monogenic arthritis (LACC1, LPIN2, MAFB, NFIL3, NOD2, PRG4, PRF1, STX11, TNFAIP3, TRHR, UNC13DI). However, the patient presented 41 risk polymorphisms for juvenile idiopathic arthritis. Thus, in the present case, arthritis seems coincidental to 22q11.2 deletion syndrome, probably caused by a multifactorial etiology. The association of the MIF gene in individuals previously described with juvenile idiopathic arthritis and 22q11.2 deletion seems unlikely since it is located in the distal and less-frequently deleted region of 22q11.2 deletion syndrome.

22q11.2 Deletion Syndrome: Influence of Parental Origin on Clinical Heterogeneity.

22q11.2 deletion syndrome (22q11.2DS) shows significant clinical heterogeneity. This study aimed to explore the association between clinical heterogeneity in 22q11.2DS and the parental origin of the deletion. The parental origin of the deletion was determined for 61 individuals with 22q11.2DS by genotyping DNA microsatellite markers and single-nucleotide polymorphisms (SNPs). Among the 61 individuals, 29 (47.5%) had a maternal origin of the deletion, and 32 (52.5%) a paternal origin. Comparison of the frequency of the main clinical features between individuals with deletions of maternal or paternal origin showed no statistically significant difference. However, Truncus arteriosus, pulmonary atresia, seizures, and scoliosis were only found in patients with deletions of maternal origin. Also, a slight difference in the frequency of other clinical features between groups of maternal or paternal origin was noted, including congenital heart disease, endocrinological alterations, and genitourinary abnormalities, all of them more common in patients with deletions of maternal origin. Although parental origin of the deletion does not seem to contribute to the phenotypic variability of most clinical signs observed in 22q11.2DS, these findings suggest that patients with deletions of maternal origin could have a more severe phenotype. Further studies with larger samples focusing on these specific features could corroborate these findings.

Variants in KMT2A in Three Individuals with Previous Suspicion of 22q11.2 Deletion Syndrome.

The condition known as 22q11.2 deletion syndrome (MIM #188400) is a rare disease with a highly variable clinical presentation including more than 180 features; specific guidelines for screening individuals have been used to support clinical suspicion before confirmatory tests by Brazil's Craniofacial Project. Of the 2568 patients listed in the Brazilian Database on Craniofacial Anomalies, 43 individuals negative for the 22q11.2 deletion syndrome were further investigated through whole-exome sequencing. Three patients (6.7%) presented with heterozygous pathogenic variants in the KMT2A gene, including a novel variant (c.6158+1del) and two that had been previously reported (c.173dup and c.3241C>T); reverse phenotyping concluded that all three patients presented features of Wiedemann-Steiner syndrome, such as neurodevelopmental disorders and dysmorphic facial features (n = 3), hyperactivity and anxiety (n = 2), thick eyebrows and lower-limb hypertrichosis (n = 2), congenital heart disease (n = 1), short stature (n = 1), and velopharyngeal insufficiency (n = 2). Overlapping features between 22q11.2 deletion syndrome and Wiedemann-Steiner syndrome comprised neuropsychiatric disorders and dysmorphic characteristics involving the eyes and nose region; velopharyngeal insufficiency was seen in two patients and is an unreported finding in WDSTS. Therefore, we suggest that both conditions should be included in each other's differential diagnoses.

Molecular investigation in individuals with orofacial clefts and microphthalmia-anophthalmia-coloboma spectrum.

This study describes genomic findings among individuals with both orofacial clefts (OC) and microphthalmia/anophthalmia/coloboma (MAC) recorded in the Brazilian Database on Craniofacial Anomalies (BDCA). Chromosomal microarray analysis (CMA) and Whole Exome Sequencing (WES) were performed in 17 individuals with OC-MAC. Clinical interpretation of molecular findings was based on data available at the BDCA and on re-examination. No copy number variants (CNVs) classified as likely pathogenic or pathogenic were detected by CMA. WES allowed a conclusive diagnosis in six individuals (35.29%), two of them with variants in the CHD7 gene, and the others with variants in the TFAP2A, POMT1, PTPN11, and TP63 genes with the following syndromes: CHARGE, CHD7-spectrum, Branchiooculofacial, POMT1-spectrum, LEOPARD, and ADULT. Variants of uncertain significance (VUS) possibly associated to the phenotypes were found in six other individuals. Among the individuals with VUSes, three individuals presented variants in genes associated to defects of cilia structure and/or function, including DYNC2H1, KIAA0586, WDR34, INTU, RPGRIP1L, KIF7, and LMNA. These results show that WES was the most effective molecular approach for OC-MAC in this cohort. This study also reinforces the genetic heterogeneity of OC-MAC, and the importance of genes related to ciliopathies in this phenotype.

SATB2-Associated Syndrome Due to a c.715C>T:p(Arg239*) Variant in Adulthood: Natural History and Literature Review.

SATB2-associated syndrome (SAS) is a rare condition, and it is characterized by severe developmental delay/intellectual disability, especially severe speech delay/or absence, craniofacial abnormalities, and behavioral problems. Most of the published reports are limited to children, with little information about the natural history of the disease and the possible novel signs and symptoms or behavioral changes in adulthood. We describe the management and follow-up of a 25-year-old male with SAS due to a de novo heterozygous nonsense variant SATB2:c.715C>T:p.(Arg239*) identified by whole-exome sequencing and review the literature. The case herein described contributes to a better characterization of the natural history of this genetic condition and in addition to the genotype-phenotype correlation of the SATB2:c.715C>T:p.(Arg239*) variant in SAS, highlights some particularities of its management.

Rare 15q21.1q22.31 Duplication Due to a Familial Chromosomal Insertion and Diagnostic Investigation in a Carrier of Balanced Chromosomal Rearrangement and Intellectual Disability.

Insertions are rare balanced chromosomal rearrangements with an increased risk of imbalances for the offspring. Moreover, balanced rearrangements in individuals with abnormal phenotypes may be associated to the phenotype by different mechanisms. This study describes a three-generation family with a rare chromosomal insertion. G-banded karyotype, chromosomal microarray analysis (CMA), whole-exome sequencing (WES), and low-pass whole-genome sequencing (WGS) were performed. Six individuals had the balanced insertion [ins(9;15)(q33;q21.1q22.31)] and three individuals had the derivative chromosome 9 [der(9)ins(9;15)(q33;q21.1q22.31)]. The three subjects with unbalanced rearrangement showed similar clinical features, including intellectual disability, short stature, and facial dysmorphisms. CMA of these individuals revealed a duplication of 19.3 Mb at 15q21.1q22.31. A subject with balanced rearrangement presented with microcephaly, severe intellectual disability, absent speech, motor stereotypy, and ataxia. CMA of this patient did not reveal pathogenic copy number variations and low-pass WGS showed a disruption of the RABGAP1 gene at the 9q33 breakpoint. This gene has been recently associated with a recessive disorder, which is not compatible with the mode of inheritance in this patient. WES revealed an 88 bp deletion in the MECP2 gene, consistent with Rett syndrome. This study describes the clinical features associated with the rare 15q21.1-q22.31 duplication and reinforces that searching for other genetic causes is warranted for individuals with inherited balanced chromosomal rearrangements and abnormal phenotypes.

Clinical and laboratory differences between chromosomal and undefined causes of non-obstructive azoospermia: A retrospective study

ABSTRACT BACKGROUND: Knowledge of clinical and laboratory differences between chromosomal and undefined causes aids etiological research on non-obstructive azoospermia. OBJECTIVE: Compare clinical and laboratory differences between men with non-obstructive azoospermia due to chromosomal anomalies versus undefined causes DESIGN AND SETTING: A cross-sectional retrospective study conducted at a public university hospital in Campinas (Brazil) METHODS: All men aged 20-40 years with non-obstructive azoospermia were included in the analysis. RESULTS: The 107 cases included 14 with Klinefelter syndrome (KS) (13%), 1 with mosaic KS, 4 with sex development disorders (2 testicular XX, 1 NR5A1 gene mutation, and 1 mild androgen insensitivity syndrome) (4%), 9 with other non-obstructive azoospermia etiologies (8%), and 79 with undefined causes. The 22 chromosomal anomaly cases (14 KS, 1 mosaic KS, 2 testicular XX, 4 sex chromosome anomalies, and 1 autosomal anomaly) were compared with the 79 undefined cause cases. The KS group had lower average testicular volume, shorter penile length, and lower total testosterone levels but greater height, arm span, serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels, and gynecomastia frequency (absent in the undefined group and affecting more than half of the KS group). Patients with testicular XX DSD had LH, FSH, and penile length data intermediate between the KS and undefined cause groups, testicular volume similar to the KS group, and other data similar to the undefined group. CONCLUSION: Clinical and laboratory data differentiate men with non-obstructive azoospermia and chromosomal anomalies, particularly KS and testicular XX, from those with undefined causes or other chromosomal anomalies.

Dual Molecular Diagnoses of Recessive Disorders in a Child from Consanguineous Parents: Case Report and Literature Review.

The widespread use of whole exome sequencing (WES) resulted in the discovery of multilocus pathogenic variations (MPV), defined as two or more distinct or overlapping Mendelian disorders occurring in a patient, leading to a blended phenotype. In this study, we report on a child with autosomal recessive primary microcephaly-5 (MCPH5) and nephropathic cystinosis. The proband is the first child of consanguineous parents, presenting a complex phenotype including neurodevelopmental delay, microcephaly, growth restriction, significant delay of bone maturation, lissencephaly, and abnormality of neuronal migration, photophobia, and renal tubular acidosis. WES revealed two pathogenic and homozygous variants: a c.4174C>T variant in the ASPM gene and a c.382C>T variant in the CTNS gene, explaining the complex phenotype. The literature review showed that most of the patients harboring two variants in recessive disease genes are born to consanguineous parents. To the best of our knowledge, the patient herein described is the first one harboring pathogenic variants in both the ASPM and CTNS genes. These findings highlight the importance of searching for MPV in patients with complex phenotypes investigated by genome-wide testing methods, especially for those patients born to consanguineous parents.

Clinical and laboratory differences between chromosomal and undefined causes of non-obstructive azoospermia: A retrospective study.

BACKGROUND: Knowledge of clinical and laboratory differences between chromosomal and undefined causes aids etiological research on non-obstructive azoospermia. OBJECTIVE: Compare clinical and laboratory differences between men with non-obstructive azoospermia due to chromosomal anomalies versus undefined causes. DESIGN AND SETTING: A cross-sectional retrospective study conducted at a public university hospital in Campinas (Brazil). METHODS: All men aged 20-40 years with non-obstructive azoospermia were included in the analysis. RESULTS: The 107 cases included 14 with Klinefelter syndrome (KS) (13%), 1 with mosaic KS, 4 with sex development disorders (2 testicular XX, 1 NR5A1 gene mutation, and 1 mild androgen insensitivity syndrome) (4%), 9 with other non-obstructive azoospermia etiologies (8%), and 79 with undefined causes. The 22 chromosomal anomaly cases (14 KS, 1 mosaic KS, 2 testicular XX, 4 sex chromosome anomalies, and 1 autosomal anomaly) were compared with the 79 undefined cause cases. The KS group had lower average testicular volume, shorter penile length, and lower total testosterone levels but greater height, arm span, serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels, and gynecomastia frequency (absent in the undefined group and affecting more than half of the KS group). Patients with testicular XX DSD had LH, FSH, and penile length data intermediate between the KS and undefined cause groups, testicular volume similar to the KS group, and other data similar to the undefined group. CONCLUSION: Clinical and laboratory data differentiate men with non-obstructive azoospermia and chromosomal anomalies, particularly KS and testicular XX, from those with undefined causes or other chromosomal anomalies.

Biallelic frameshift variant in the TBC1D2B gene in two siblings with progressive gingival overgrowth, fibrous dysplasia of face, and mental deterioration.

Biallelic loss-of-function variants in the TBC1D2B gene were recently reported as a cause of a neurodevelopmental disorder with seizures and gingival overgrowth. Here, we report two male siblings with the similar clinical characteristics. They started with gingival overgrowth and bilateral growth of soft tissues in the malar region at 3 years of age, which evolved with significant maxillary hypertrophy and compression of the brainstem due to fibrous dysplasia of facial bones. After disease evolution, they presented with mental deterioration, limb tremors, and gait ataxia. One of them also presented with seizures. Whole exome sequencing revealed a novel biallelic frameshift variant [c.595del; p.(Val199Trpfs*22)] in the TBC1D2B gene in both patients, which was confirmed and found in heterozygous state in each of their parents. There are strong similarities in clinical characteristics, age of onset, and evolution between the patients described here and cases reported in the literature, including cherubism-like phenotype with progressive gingival overgrowth and seizures. This is the fourth family in the world in which a biallelic loss-of-function variant in the TBC1D2B gene is associated with this phenotype. These results support that loss of TBC1D2B is the cause of this rare condition.

Increased runs of homozygosity in the autosomal genome of Brazilian individuals with neurodevelopmental delay/intellectual disability and/or multiple congenital anomalies investigated by chromosomal microarray analysis.

Runs of homozygosity (ROH) in the human genome may be clinically relevant. The aim of this study was to report the frequency of increased ROH of the autosomal genome in individuals with neurodevelopmental delay/intellectual disability and/or multiple congenital anomalies, and to compare these data with a control group. Data consisted of calls of homozygosity from 265 patients and 289 controls. In total, 7.2% (19/265) of the patients showed multiple ROH exceeding 1% of autosomal genome, compared to 1.4% (4/289) in the control group (p=0.0006). Homozygosity ranged from 1.38% to 22.12% among patients, and from 1.53 to 2.40% in the control group. In turn, 1.9% (5/265) of patients presented ROH ≥10Mb in a single chromosome, compared to 0.3% (1/289) of individuals from the control group (p=0.0801). By excluding cases with reported consanguineous parents (15/24), the frequency of increased ROH was 3.4% (9/250) among patients and 1.7% (5/289) in the control group, considering multiple ROH exceeding 1% of the autosome genome and ROH ≥10Mb in a single chromosome together, although not statistically significant (p=0.1873). These results reinforce the importance of investigating ROH, which with complementary diagnostic tests can improve the diagnostic yield for patients with such conditions.

Brazil's Craniofacial Project: Different approaches on orofacial clefts and 22q11.2 deletion syndrome.

This article reports the present situation of Brazilian health care in genetics for Orofacial Cleft (OFC) and 22q11.2 Deletions Syndrome (22q11.2 DS) based on research conducted by Brazil's Craniofacial Project (BCFP). Established in 2003, BCFP is a voluntary and cooperative network aiming to investigate the health care of people with these diseases and other craniofacial anomalies. The initiatives and research results are presented in four sections: (a) a comprehensive report of the Brazilian public health system in craniofacial genetics; (b) multicentric studies developed on OFC and 22q11.2 DS; (c) education strategies focused on addressing these conditions for both population and health-care professionals; and (d) the nosology through the Brazilian Database on Craniofacial Anomalies (BDCA). Since 2006, BDCA uses a standardized method with detailed clinical data collection, which allows for conducting studies on nosology, genotype-phenotype correlations, and natural history; data can also contribute to public policies. Currently, the BDCA stores data on 1,724 individuals, including 1,351 (78.36%) who were primarily admitted due to OFC and 373 (21.63%) with clinical suspicion of 22q11.2 DS. Chromosomal abnormalities/genomic imbalances were represented by 92/213 (43.19%) individuals with syndromic OFC, including 43 with 22q11.2 DS, which indicates the need for chromosomal microarray analysis in this group. The nosologic diversity reinforces that monitoring clinical is the best strategy for etiological investigation. BCFP's methodology has introduced the possibility of increasing scientific knowledge and genetic diagnosis of OFC and 22q11.2 DS to in turn improve health care and policies for this group of diseases.

A recognizable phenotype related to 19p13.12 microdeletion.

Submicroscopic deletions in chromosome 19 have been rarely reported. We reported a male patient presenting with neurodevelopmental delay and facial dysmorphisms with a de novo 19p13.11p13.12 deletion of approximately 1.4 Mb. To date, there are seven cases with deletions overlapping the 19p13.11-p13.12 region described in the literature. A region of 800 kb for branchial arch defects in the proximal region of 19p13.12, and another minimal critical region of 305 kb for hypertrichosis, synophrys, and protruding front teeth have been proposed previously. We suggest that the shortest region of overlap could be refined to an approximately 53 kb region shared within all patients, encompassing part of BRD4 and AKAP8L genes and the AKAP8 gene. Based on the genotype-phenotype correlation of the present case and cases with overlapping deletions described in the literature, it was possible to recognize a consistent phenotype characterized by microcephaly, ear abnormalities, rounded face, synophrys, arched or upwardly angulated eyebrows, short nose, anteverted nares, prominent cheeks, teeth abnormalities, and developmental delay.

Genomic imbalances in syndromic congenital heart disease / Desequilíbrios genômicos na cardiopatia congênita sindrômica

Abstract Objective: To identify pathogenic genomic imbalances in patients presenting congenital heart disease (CHD) with extra cardiac anomalies and exclusion of 22q11.2 deletion syndrome (22q11.2 DS). Methods: 78 patients negative for the 22q11.2 deletion, previously screened by fluorescence in situ hybridization (FISH) and/or multiplex ligation probe amplification (MLPA) were tested by chromosomal microarray analysis (CMA). Results: Clinically significant copy number variations (CNVs ≥300 kb) were identified in 10% (8/78) of cases. In addition, potentially relevant CNVs were detected in two cases (993 kb duplication in 15q21.1 and 706 kb duplication in 2p22.3). Genes inside the CNV regions found in this study, such as IRX4, BMPR1A, SORBS2, ID2, ROCK2, E2F6, GATA4, SOX7, SEMAD6D, FBN1, and LTPB1 are known to participate in cardiac development and could be candidate genes for CHD. Conclusion: These data showed that patients presenting CHD with extra cardiac anomalies and exclusion of 22q11.2 DS should be investigated by CMA. The present study emphasizes the possible role of CNVs in CHD.

Resumo Objetivo: Identificar desequilíbrios genômicos patogênicos em pacientes que apresentam cardiopatias congênitas (CC) e anomalias extracardíacas e exclusão da síndrome de deleção 22q11.2 (SD22q11.2). Métodos: Foram avaliados por microarray cromossômico (CMA) 78 pacientes negativos para a deleção 22q11.2, previamente testados por hibridação in situ com fluorescência (FISH) e/ou amplificação de múltiplas sondas dependentes de ligação (MLPA). Resultados: Foram identificadas variações do número de cópias de DNA (CNVs) clinicamente significativas (≥ 300 kb) em 10% (8/78) dos casos, além de CNVs potencialmente relevantes em dois casos (duplicação de 993 kb em 15q21.1 e duplicação de 706 kb em 2p22.3). Genes envolvidos como IRX4, BMPR1A, SORBS2, ID2, ROCK2, E2F6, GATA4, SOX7, SEMAD6D, FBN1 e LTPB1 são conhecidos por atuar no desenvolvimento cardíaco e podem ser genes candidatos a CC. Conclusão: Esses dados mostram que pacientes que apresentam CC, com anomalias extracardíacas e exclusão da SD22q11.2, devem ser investigados por CMA. Ainda, este estudo enfatiza a possível função das CNVs nas CC.

A boy with partial dup(18q)/del(18p) due to a maternal pericentric inversion: Genotype-phenotype correlation and risk of recombinant chromosomes based on systematic review of the literature.

We report a boy carrying a recombinant chromosome 18, with terminal deletion of 10.8 Mb from 18p11.32 to 18p11.21 and a terminal duplication of 22.8 Mb from 18q21.31 to 18q23, resulting from a maternal pericentric inversion of the chromosome 18. He presented with poor growth, developmental delay, facial dysmorphisms, surgically repaired left cleft lip and palate, a mild form of holoprosencephaly characterized by single central incisor and agenesis of the septum pellucidum, and body asymmetry. Based on the systematic review of the literature, we discuss genotype-phenotype correlation and the risk for the recombinants of pericentric inversions of chromosome 18. © 2016 Wiley Periodicals, Inc.

Distal 22q11.2 microduplication combined with typical 22q11.2 proximal deletion: a case report.

The 22q11 chromosomal region contains low copy repeats (LCRs) sequences that mediate non-allelic homologous recombination, which predisposes to copy number variations (CNVs) at this locus. Hemizygous deletions of the proximal 22q11.2 region result in the 22q11.2 deletion syndrome (22q11.2 DS). In addition, 22q11.2 duplications involving the distal LCR22s have been reported. This article describes a patient presenting a 2.5-Mb de novo deletion at proximal 22q11.21 region (between LCRs A-D), combined with a 1.3-Mb maternally inherited duplication at distal 22q11.23 region (between LCRs F-H). The presence of concomitant chromosomal imbalances found in this patient has not been reported previously. Clinical and molecular data were compared with literature, in order to contribute to genotype-phenotype correlation. These findings exemplify the complexity and genetic heterogeneity observed in 22q11.2 deletion syndrome and highlights the difficulty to make genetic counseling and predict phenotypic consequences in these situations.

Clinical, cytogenetic, and molecular characterization of six patients with ring chromosomes 22, including one with concomitant 22q11.2 deletion.

We report here on six patients with a ring chromosome 22 and the range of cytogenetic and phenotypic features presented by them. Genomic analysis was carried out using classical and molecular cytogenetics, MLPA (Multiplex Ligation-dependent Probe Amplification) and genome-wide SNP-array analysis. The ring was found in all patients, but Patient 6 displayed constitutional mosaicism with a normal cell line. Five patients had deletions in the ring chromosome 22, and in four of them the breakpoints--unique for each patient--could be identified by genome-wide SNP-array analysis. One patient presented with a 22q11.2 deletion concomitant with the deletion caused by the ring formation. Common phenotypic features included autism, speech delay and seizures, as previously reported for individuals with r(22) and/or 22q13.3 deletions. Investigation of the genes within the deletions revealed multiple genes related to development of the central nervous system, psychomotor delay, severe language impairment, hypotonia, and autistic symptoms. There was no clear correlation between the severity of clinical features and the size of the deleted segment. This study underscores the variability in ring structure and clinical presentation of the r(22) and adds information to the limited literature on this rare disorder.