Truncating variants of the sterol recognition region of SHH cause hypertelorism phenotype rather than hypotelorism-holoprosencephaly.

Sonic hedgehog signaling molecule (SHH) is a key molecule in the cilia-mediated signaling pathway and a critical morphogen in embryogenesis. The association between loss-of-function variants of SHH and holoprosencephaly is well established. In mice experiments, reduced or increased signaling of SHH have been shown to be associated with narrowing or excessive expansion of the facial midline, respectively. Herein, we report two unrelated patients with de novo truncating variants of SHH presenting with hypertelorism rather than hypotelorism. The first patient was a 13-year-old girl. Her facial features included hypertelorism, strabismus, telecanthus, malocclusion, frontal bossing, and wide widow's peak. She had borderline developmental delay and agenesis of the corpus callosum. She had a nonsense variant of SHH: Chr7(GRCh38):g.155802987C > T, NM_000193.4:c.1302G > A, p.(Trp434*). The second patient was a 25-year-old girl. Her facial features included hypertelorism and wide widow's peak. She had developmental delay and agenesis of the corpus callosum. She had a frameshift variant of SHH: Chr7(GRCh38):g.155803072_155803074delCGGinsT, NM_000193.4:c.1215_1217delCCGinsA, p.(Asp405Glufs*92). The hypertelorism phenotype contrasts sharply with the prototypical hypotelorism-holoprosencephaly phenotype associated with loss-of-function of SHH. We concluded that a subset of truncating variants of SHH could be associated with hypertelorism rather than hypotelorism.

Clinical diversity and molecular mechanism of VPS35L-associated Ritscher-Schinzel syndrome.

PURPOSE: The Retriever subunit VPS35L is the third responsible gene for Ritscher-Schinzel syndrome (RSS) after WASHC5 and CCDC22. To date, only one pair of siblings have been reported and their condition was significantly more severe than typical RSS. This study aimed to understand the clinical spectrum and underlying molecular mechanism in VPS35L-associated RSS. METHODS: We report three new patients with biallelic VPS35L variants. Biochemical and cellular analyses were performed to elucidate disease aetiology. RESULTS: In addition to typical features of RSS, we confirmed hypercholesterolaemia, hypogammaglobulinaemia and intestinal lymphangiectasia as novel complications of VPS35L-associated RSS. The latter two complications as well as proteinuria have not been reported in patients with CCDC22 and WASHC5 variants. One patient showed a severe phenotype and the other two were milder. Cells established from patients with the milder phenotypes showed relatively higher VPS35L protein expression. Cellular analysis found VPS35L ablation decreased the cell surface level of lipoprotein receptor-related protein 1 and low-density lipoprotein receptor, resulting in reduced low-density lipoprotein cellular uptake. CONCLUSION: VPS35L-associated RSS is a distinct clinical entity with diverse phenotype and severity, with a possible molecular mechanism of hypercholesterolaemia. These findings provide new insight into the essential and distinctive role of Retriever in human development.

Breakpoints in complex chromosomal rearrangements correspond to transposase-accessible regions of DNA from mature sperm.

Constitutional complex chromosomal rearrangements (CCRs) are rare cytogenetic aberrations arising in the germline via an unknown mechanism. Here we analyzed the breakpoint junctions of microscopically three-way or more complex translocations using comprehensive genomic and epigenomic analyses. All of these translocation junctions showed submicroscopic genomic complexity reminiscent of chromothripsis. The breakpoints were clustered within small genomic domains with junctions showing microhomology or microinsertions. Notably, all of the de novo cases were of paternal origin. The breakpoint distributions corresponded specifically to the ATAC-seq (assay for transposase-accessible chromatin with sequencing) read data peak of mature sperm and not to other chromatin markers or tissues. We propose that DNA breaks in CCRs may develop in an accessible region of densely packaged chromatin during post-meiotic spermiogenesis.

Angelman syndrome with mosaic paternal uniparental disomy suggestive of mitotic nondisjunction.

Angelman syndrome (AS) is caused by the functional absence of the maternal ubiquitin-protein ligase E3A (UBE3A) gene. Approximately 5% of AS is caused by paternal uniparental disomy of chromosome 15 (UPD(15)pat), most of which is considered to result from monosomy rescue. However, little attention has focused on how UPD(15)pat occurs. We suggest the mitotic nondisjunction mechanism as a cause of UPD(15)pat in a six-year-old patient presenting with distinctive characteristics in line with AS. DNA methylation screening of 15q11-q13 showed a paternal band and a faint maternal band, suggestive of mosaic status. By trio-based microsatellite analysis, we confirmed a large proportion of UPD(15)pat cells and a small proportion of cells of biparental origin. Single nucleotide polymorphism (SNP) microarray revealed isodisomy of the entire chromosome 15. These results suggest that the UPD(15)pat of the patient resulted from mitotic nondisjunction, which may also be the cause of other cases of AS with UPD(15)pat.

A Syndromic Neurodevelopmental Disorder Caused by Mutations in SMARCD1, a Core SWI/SNF Subunit Needed for Context-Dependent Neuronal Gene Regulation in Flies.

Mutations in several genes encoding components of the SWI/SNF chromatin remodeling complex cause neurodevelopmental disorders (NDDs). Here, we report on five individuals with mutations in SMARCD1; the individuals present with developmental delay, intellectual disability, hypotonia, feeding difficulties, and small hands and feet. Trio exome sequencing proved the mutations to be de novo in four of the five individuals. Mutations in other SWI/SNF components cause Coffin-Siris syndrome, Nicolaides-Baraitser syndrome, or other syndromic and non-syndromic NDDs. Although the individuals presented here have dysmorphisms and some clinical overlap with these syndromes, they lack their typical facial dysmorphisms. To gain insight into the function of SMARCD1 in neurons, we investigated the Drosophila ortholog Bap60 in postmitotic memory-forming neurons of the adult Drosophila mushroom body (MB). Targeted knockdown of Bap60 in the MB of adult flies causes defects in long-term memory. Mushroom-body-specific transcriptome analysis revealed that Bap60 is required for context-dependent expression of genes involved in neuron function and development in juvenile flies when synaptic connections are actively being formed in response to experience. Taken together, we identify an NDD caused by SMARCD1 mutations and establish a role for the SMARCD1 ortholog Bap60 in the regulation of neurodevelopmental genes during a critical time window of juvenile adult brain development when neuronal circuits that are required for learning and memory are formed.

Missense Mutations in NKAP Cause a Disorder of Transcriptional Regulation Characterized by Marfanoid Habitus and Cognitive Impairment.

NKAP is a ubiquitously expressed nucleoplasmic protein that is currently known as a transcriptional regulatory molecule via its interaction with HDAC3 and spliceosomal proteins. Here, we report a disorder of transcriptional regulation due to missense mutations in the X chromosome gene, NKAP. These mutations are clustered in the C-terminal region of NKAP where NKAP interacts with HDAC3 and post-catalytic spliceosomal complex proteins. Consistent with a role for the C-terminal region of NKAP in embryogenesis, nkap mutant zebrafish with a C-terminally truncated NKAP demonstrate severe developmental defects. The clinical features of affected individuals are highly conserved and include developmental delay, hypotonia, joint contractures, behavioral abnormalities, Marfanoid habitus, and scoliosis. In affected cases, transcriptome analysis revealed the presence of a unique transcriptome signature, which is characterized by the downregulation of long genes with higher exon numbers. These observations indicate the critical role of NKAP in transcriptional regulation and demonstrate that perturbations of the C-terminal region lead to developmental defects in both humans and zebrafish.

Target enrichment long-read sequencing with adaptive sampling can determine the structure of the small supernumerary marker chromosomes.

Structural analysis of small supernumerary marker chromosomes (sSMCs) has revealed that many have complex structures. Structural analysis of sSMCs by whole genome sequencing using short-read sequencers is challenging however because most present with a low level of mosaicism and consist of a small region of the involved chromosome. In this present study, we applied adaptive sampling using nanopore long-read sequencing technology to enrich the target region and thereby attempted to determine the structure of two sSMCs with complex structural rearrangements previously revealed by cytogenetic microarray. In adaptive sampling, simple specification of the target region in the FASTA file enables to identify whether or not the sequencing DNA is included in the target, thus promoting efficient long-read sequencing. To evaluate the target enrichment efficiency, we performed conventional pair-end short-read sequencing in parallel. Sequencing with adaptive sampling achieved a target enrichment at about a 11.0- to 11.5-fold higher coverage rate than conventional pair-end sequencing. This enabled us to quickly identify all breakpoint junctions and determine the exact sSMC structure as a ring chromosome. In addition to the microhomology and microinsertion at the junctions, we identified inverted repeat structure in both sSMCs, suggesting the common generation mechanism involving replication impairment. Adaptive sampling is thus an easy and beneficial method of determining the structures of complex chromosomal rearrangements.

The novel and recurrent variants in exon 31 of CREBBP in Japanese patients with Menke-Hennekam syndrome.

Menke-Hennekam syndrome-1 (MKHK1) is a congenital disorder caused by the heterozygous variants in exon 30 or 31 of CREBBP (CREB binding protein) gene mapped on 16p13.3. It is characterized by psychomotor delay, variable impairment of intellectual disability (ID), feeding difficulty, autistic behavior, hearing impairment, short stature, microcephaly, and facial dysmorphisms. The CREBBP loss-of-function variants cause Rubinstein-Taybi syndrome-1 (RSTS1). The function of CREBBP leading to MKHK1 has not been clarified so far, and the phenotype of MKHK1 significantly differs from that of RSTS1. We examined six patients with de novo pathogenic variants affecting the last exon of CREBBP, and they shared the clinical features of MKHK1. This study revealed that one frameshift and three nonsense variants of CREBBP cause MKHK1, and inferred that the nonsense variants of the last exon could further help in the elucidation of the etiology of MKHK1.

CDK19-related disorder results from both loss-of-function and gain-of-function de novo missense variants.

PURPOSE: To expand the recent description of a new neurodevelopmental syndrome related to alterations in CDK19. METHODS: Individuals were identified through international collaboration. Functional studies included autophosphorylation assays for CDK19 Gly28Arg and Tyr32His variants and in vivo zebrafish assays of the CDK19G28R and CDK19Y32H. RESULTS: We describe 11 unrelated individuals (age range: 9 months to 14 years) with de novo missense variants mapped to the kinase domain of CDK19, including two recurrent changes at residues Tyr32 and Gly28. In vitro autophosphorylation and substrate phosphorylation assays revealed that kinase activity of protein was lower for p.Gly28Arg and higher for p.Tyr32His substitutions compared with that of the wild-type protein. Injection of CDK19 messenger RNA (mRNA) with either the Tyr32His or the Gly28Arg variants using in vivo zebrafish model significantly increased fraction of embryos with morphological abnormalities. Overall, the phenotype of the now 14 individuals with CDK19-related disorder includes universal developmental delay and facial dysmorphism, hypotonia (79%), seizures (64%), ophthalmologic anomalies (64%), and autism/autistic traits (56%). CONCLUSION: CDK19 de novo missense variants are responsible for a novel neurodevelopmental disorder. Both kinase assay and zebrafish experiments showed that the pathogenetic mechanism may be more diverse than previously thought.

Clinical delineation, sex differences, and genotype-phenotype correlation in pathogenic KDM6A variants causing X-linked Kabuki syndrome type 2.

PURPOSE: The variant spectrum and the phenotype of X-linked Kabuki syndrome type 2 (KS2) are poorly understood. METHODS: Genetic and clinical details of new and published individuals with pathogenic KDM6A variants were compiled and analyzed. RESULTS: Sixty-one distinct pathogenic KDM6A variants (50 truncating, 11 missense) from 80 patients (34 males, 46 females) were identified. Missense variants clustered in the TRP 2, 3, 7 and Jmj-C domains. Truncating variants were significantly more likely to be de novo. Thirteen individuals had maternally inherited variants and one had a paternally inherited variant. Neonatal feeding difficulties, hypoglycemia, postnatal growth retardation, poor weight gain, motor delay, intellectual disability (ID), microcephaly, congenital heart anomalies, palate defects, renal malformations, strabismus, hearing loss, recurrent infections, hyperinsulinism, seizures, joint hypermobility, and gastroesophageal reflux were frequent clinical findings. Facial features of over a third of patients were not typical for KS. Males were significantly more likely to be born prematurely, have shorter stature, and severe developmental delay/ID. CONCLUSION: We expand the KDM6A variant spectrum and delineate the KS2 phenotype. We demonstrate that the variability of the KS2 phenotypic depends on sex and the variant type. We also highlight the overlaps and differences between the phenotypes of KS2 and KS1.

A novel missense variant in CUL3 shows altered binding ability to BTB-adaptor proteins leading to diverse phenotypes of CUL3-related disorders.

CUL3 forms Cullin-Ring ubiquitin ligases (CRL) with Ring-box protein and BTB-adaptor proteins. A variety of BTB-adaptor proteins have been reported to interact with the N-terminus of CUL3, which makes it possible to recognize various substrates for degradation. Regarding the association of CUL3 with neurodevelopmental disorders, a recent study reported three patients with global developmental delay, who carried de novo variants in CUL3. Here, we describe a novel de novo CUL3 variant (c.158G > A, p.Ser53Asn) identified in a patient with global developmental delay, who presented some novel dysmorphic features, including macrocephaly, characteristic facial features, and cutis marmorata. Immunoprecipitation and immunoblot analyses identified significantly weaker binding ability to some BTB proteins in CUL3-S53N compared to wild-type. Interestingly, label-free quantification proteomics analysis of samples immunoprecipitated by CUL3-S53N showed a significantly decreased interaction with some BTB proteins, while almost equal interaction or significantly increased interaction was observed with other BTB proteins. The binding between CUL3 and BTB proteins is essential for CRL substrate recognition, and alteration of their interaction is thought to result in the quantitative alteration in substrate proteins. It is possible that the difference of dysmorphic features between the present case and previously reported cases is caused by the distinctive effect of each CUL3 variant on substrate proteins. The clinical information of the present case will expand the picture of CUL3-related global developmental disorders, and subsequent cell biological analysis of the novel mutation will provide insight into the underlying molecular mechanism of how CUL3 pathogenic variants cause neurological disorders.

Biallelic loss of OTUD7A causes severe muscular hypotonia, intellectual disability, and seizures.

The heterozygous deletion of 15q13.3 is a recurrently observed microdeletion syndrome associated with a relatively mild phenotype including learning disability and language impairment. In contrast, the homozygous deletion of 15q13.3 is extremely rare and is associated with a much severer phenotype that includes epileptic encephalopathy, profound intellectual disability, and hypotonia. Which of the genes within the deleted interval is responsible for the more severe features when biallelically deleted is currently unknown. Here, we report a patient with profound hypotonia, severe intellectual disability, and seizures who had biallelic loss-of-function variants in OTUD7A: a 15q13.3 deletion including the OTUD7A locus, and a frameshift OTUD7A variant c.1125del, p.(Glu375Aspfs*11). Unexpectedly, both aberrations occurred de novo. Our experiment using Caenorhabditis elegans showed that worms carrying a corresponding homozygous variant in the homolog OTUB-2 exhibited weakened muscle contraction suggestive of aberrant neuromuscular transmission. We concluded that the biallelic complete loss of OTUD7A in humans represents a presumably new autosomal recessive disorder characterized by profound hypotonia, severe intellectual disability, and seizures.

Expanding the phenotype of biallelic loss-of-function variants in the NSUN2 gene: Description of four individuals with juvenile cataract, chronic nephritis, or brain anomaly as novel complications.

The NSUN2 gene encodes a tRNA cytosine methyltransferase that functions in the maturation of leucyl tRNA (Leu) (CAA) precursors, which is crucial for the anticodon-codon pairing and correct translation of mRNA. Biallelic loss of function variants in NSUN2 are known to cause moderate to severe intellectual disability. Microcephaly, postnatal growth retardation, and dysmorphic facial features are common complications in this genetic disorder, and delayed puberty is occasionally observed. Here, we report four individuals, two sets of siblings, with biallelic loss-of-function variants in the NSUN2 gene. The first set of siblings have compound heterozygous frameshift variants: c.546_547insCT, p.Met183Leufs*13; c.1583del, p.Pro528Hisfs*19, and the other siblings carry a homozygous frameshift variant: c.1269dup, p.Val424Cysfs*14. In addition to previously reported clinical features, the first set of siblings showed novel complications of juvenile cataract and chronic nephritis. The other siblings showed hypomyelination and simplified gyral pattern in neuroimaging. NSUN2-related intellectual disability is a very rare condition, and less than 20 cases have been reported previously. Juvenile cataract, chronic nephritis, and brain anomaly shown in the present patients have not been previously described. Our report suggests clinical diversity of NSUN2-related intellectual disability.

R3HDM1 haploinsufficiency is associated with mild intellectual disability.

R3HDM1 (R3H domain containing 1) is an uncharacterized RNA-binding protein that is highly expressed in the human cerebral cortex. We report the first case of a 12-year-old Japanese male with haploinsufficiency of R3HDM1. He presented with mild intellectual disability (ID) and developmental delay. He had a pericentric inversion of 46,XY,inv(2)(p16.1q21.3)dn with breakpoints in intron 19 of R3HDM1 (2q21.3) and the intergenic region (2p16.1). The R3HDM1 levels in his lymphoblastoid cells were reduced to approximately half that of the healthy controls. However, the expression of MIR128-1, in intron 18 of R3HDM1, was not affected via the pericentric inversion. Knockdown of R3HDM1 in mouse embryonic hippocampal neurons suppressed dendritic growth and branching. Notably, the Database of Genomic Variants reported the case of a healthy control with a 488-kb deletion that included both R3HDM1 and MIR128-1. miR-128 has been reported to inhibit dendritic growth and branching in mouse brain neurons, which directly opposes the novel functions of R3HDM1. These findings suggest that deleting both R3HDM1 and MIR128-1 alleviates the symptoms of the disease caused by loss-of-function mutations in R3HDM1 only. Thus, haploinsufficiency of R3HDM1 in the patient may be the cause of the mild ID due to the genetic imbalance between R3HDM1 and MIR128-1.

The involvement of U-type dicentric chromosomes in the formation of terminal deletions with or without adjacent inverted duplications.

An inverted duplication with a terminal deletion (inv-dup-del) is one of the complex constitutional structural rearrangements that can occur in a chromosome. Although breakages of dicentric chromosome have been suggested, the precise mechanism of this is yet to be fully understood. In our present study, we investigated the genomic structure of 10 inv-dup-del cases to elucidate this mechanism. Two recurrent 8p inv-dup-del cases harbored a large copy-number-neutral region between the duplication and deletion in common. Although the other non-recurrent cases did not appear to have this copy-number-neutral region, refined sequencing analysis identified that they contained a small intervening region at the junction between the inverted and non-inverted segment. The size of this small intervening region ranged from 1741 to 3728 bp. Combined with a presence of microhomology at the junction, a resolution of the replication fork stalling through template switching within the same replication fork is suggested. We further observed two cases with mosaicism of the dicentric chromosome and various structural rearrangements related to the dicentric chromosome. Refined analysis allowed us to identify different breakpoints on the same chromosome in the same case, implicating multiple rounds of U-type formation and its breakage. From these results, we propose that a replication-based mechanism generates unstable dicentric chromosomes and that their breakage leads to the formation of inv-dup-dels and other related derivative chromosomes.

Analysis of the Origin of Double Mosaic Aneuploidy in Two Cases.

We present 2 cases of double mosaic aneuploidy harboring 2 or more different aneuploid cell lines, but no line with a normal chromosome constitution. One of these cases presented mosaicism of sex chromosome aneuploid cell lines (47,XXX/45,X) along with another line containing an autosomal trisomy (47,XX,+8), while the other case showed mosaicism of 2 different autosomal trisomy cell lines (47,XY,+5 and 47,XY,+8). To elucidate the mechanisms underlying these mosaicisms, we conducted molecular cytogenetic analyses. Genotyping data from the SNP microarray indicated that 2 sequential meiotic or early postzygotic segregation errors likely had occurred followed by natural selection. These cases suggest that frequent segregation errors and selection events in the meiotic and early postzygotic stages lead to this condition.

Gait characteristics of children with Williams syndrome with impaired visuospatial recognition: a three-dimensional gait analysis study.

Williams syndrome (WS) is a genetically based neurodevelopmental disorder characterized by intellectual disability and impaired visuospatial recognition. The aim of this study was to analyze the gait characteristics of WS children with impaired visuospatial recognition using a three-dimensional gait analysis (3DGA) to clarify the gait adaptation needed to compensate for it. 3DGA was performed in 8 WS children with impaired visuospatial recognition (mean age, 11.8 years) and 9 age-, sex-, height-, and weight-matched controls. Clinical data, fundamental motor tests, and gait variables while walking on a flat surface and walking up a mat were compared between the two groups, and the correlations between variables were analyzed in the WS children. WS children showed impairment of balance function without muscle weakness. In walking on a flat surface, the WS group showed reduced walking speed, short step length, increased variability of step length, increased knee flexion throughout the stance phase, increased horizontal pelvic range of motion (ROM), and a low Gait Deviation Index and a high Gait Profile Score, which are indices of gait quality. In walking up a mat, the WS group showed further reduced walking speed and decreased sagittal hip flexion and ankle dorsiflexion ROM in the swing phase. Impaired balance function was significantly correlated with increased variability of step length and decreased sagittal ankle dorsiflexion ROM in the swing phase. The detailed gait pattern of WS children with impaired visuospatial recognition was presented. These findings show that impaired visuospatial recognition and balance function contribute to gait adaptation.

Delineation of LZTR1 mutation-positive patients with Noonan syndrome and identification of LZTR1 binding to RAF1-PPP1CB complexes.

RASopathies are a group of developmental disorders caused by mutations in genes that regulate the RAS/MAPK pathway and include Noonan syndrome (NS), Costello syndrome, cardiofaciocutaneous syndrome and other related disorders. Whole exome sequencing studies recently identified LZTR1, PPP1CB and MRAS as new causative genes in RASopathies. However, information on the phenotypes of LZTR1 mutation-positive patients and functional properties of the mutations are limited. To identify variants of LZTR1, PPP1CB, and MRAS, we performed a targeted next-generation sequencing and reexamined previously analyzed exome data in 166 patients with suspected RASopathies. We identified eight LZTR1 variants, including a de novo variant, in seven probands who were suspicious for NS and one known de novo PPP1CB variant in a patient with NS. One of the seven probands had two compound heterozygous LZTR1 variants, suggesting autosomal recessive inheritance. All probands with LZTR1 variants had cardiac defects, including hypertrophic cardiomyopathy and atrial septal defect. Five of the seven probands had short stature or intellectual disabilities. Immunoprecipitation of endogenous LZTR1 followed by western blotting showed that LZTR1 bound to the RAF1-PPP1CB complex. Cells transfected with a small interfering RNA against LZTR1 exhibited decreased levels of RAF1 phosphorylated at Ser259. These are the first results to demonstrate LZTR1 in association with the RAF1-PPP1CB complex as a component of the RAS/MAPK pathway.

Genetic abnormalities in a large cohort of Coffin-Siris syndrome patients.

Coffin-Siris syndrome (CSS, MIM#135900) is a congenital disorder characterized by coarse facial features, intellectual disability, and hypoplasia of the fifth digit and nails. Pathogenic variants for CSS have been found in genes encoding proteins in the BAF (BRG1-associated factor) chromatin-remodeling complex. To date, more than 150 CSS patients with pathogenic variants in nine BAF-related genes have been reported. We previously reported 71 patients of whom 39 had pathogenic variants. Since then, we have recruited an additional 182 CSS-suspected patients. We performed comprehensive genetic analysis on these 182 patients and on the previously unresolved 32 patients, targeting pathogenic single nucleotide variants, short insertions/deletions and copy number variations (CNVs). We confirmed 78 pathogenic variations in 78 patients. Pathogenic variations in ARID1B, SMARCB1, SMARCA4, ARID1A, SOX11, SMARCE1, and PHF6 were identified in 48, 8, 7, 6, 4, 1, and 1 patients, respectively. In addition, we found three CNVs including SMARCA2. Of particular note, we found a partial deletion of SMARCB1 in one CSS patient and we thoroughly investigated the resulting abnormal transcripts.

SATB2-associated syndrome in patients from Japan: Linguistic profiles.

Cleft palate can be classified as either syndromic or nonsyndromic. SATB2-associated syndrome is one example of a syndromic cleft palate that is accompanied by intellectual disability, and various dental anomalies. SATB2-associated syndrome can be caused by several different molecular mechanisms including intragenic mutations and deletions of SATB2. Here, we report two patients with SATB2 truncating mutations (p.Arg239* and p.Asp702Thrfs*38) and one with a 4.4 megabase deletion including the SATB2 locus. All three patients had cleft palate and other dysmorphic features including macrodontia wide diastema. None of the three patients had acquired any meaningful words at the age of 5 years. In a review of the linguistic natural history of presently reported three patients and 30 previously reported patients, only two patients had attained verbal skills beyond speaking a few words. This degree of delayed speech contrasts with that observed in the prototypic form of syndromic cleft palate, 22q11.2 deletion syndrome. The recognition of SATB2-associated syndrome prior to palatoplasty would be important for plastic surgeons and the families of patients because precise diagnosis should provide predictive information regarding the future linguistic and intellectual abilities of the patients. Macrodontia with a wide diastema and cleft palate is a helpful and highly suggestive sign for the diagnosis of SATB2-associated syndrome.