Microdeletion of 16q24.1-q24.2-A unique etiology of Lymphedema-Distichiasis syndrome and neurodevelopmental disorder.

Interstitial deletions of 16q24.1-q24.2 are associated with alveolar capillary dysplasia, congenital renal malformations, neurodevelopmental disorders, and congenital abnormalities. Lymphedema-Distichiasis syndrome (LDS; OMIM # 153400) is a dominant condition caused by heterozygous pathogenic variants in FOXC2. Usually, lymphedema and distichiasis occur in puberty or later on, and affected individuals typically achieve normal developmental milestones. Here, we describe a boy with congenital lymphedema, distichiasis, bilateral hydronephrosis, and global developmental delay, with a de novo microdeletion of 894 kb at 16q24.1-q24.2. This report extends the phenotype of both 16q24.1-q24.2 microdeletion syndrome and of LDS. Interestingly, the deletion involves only the 3'-UTR part of FOXC2.

A Paternal "Balanced" Chromosome 2 and 4 Translocation with Chromosome 21q Insertion Leading to Duplication of 2q22.1q24.1 in Two Siblings.

Complex chromosomal rearrangements (CCRs) have been described as alterations between two or more chromosomes with at least 3 breakpoints. CCRs can cause copy number variations (CNVs) resulting in developmental disorders, multiple congenital anomalies, and recurrent miscarriages. Developmental disorders are an important health problem affecting 1-3% of children. The underlying etiology can be explained by CNV analysis in 10-20% of children who have unexplained intellectual disability, developmental delay, and congenital anomalies. Here we report two siblings who were referred to us with intellectual disability, neurodevelopmental delay, happy demeanor, and craniofacial dysmorphism due to chromosome 2q22.1q24.1 duplication. Segregation analysis showed that the duplication originated from meiotic segregation of a paternal translocation between chromosomes 2 and 4 with chromosome 21q insertion. Considering that infertility is seen in many male individuals with CCRs, it is remarkable that the father does not have any fertility problems. Gain of chromosome 2q22.1q24.1 was responsible for the phenotype due to its size and presence of a gene with a probability of being triplosensitive. We corroborate the assumption that the major gene responsible for the phenotype in the 2q23.1 region is methyl-CpG-binding domain 5, MBD5.

Deletion at an 1q24 locus reveals a critical role of long noncoding RNA DNM3OS in skeletal development.

BACKGROUND: Skeletal development and maintenance are complex processes known to be coordinated by multiple genetic and epigenetic signaling pathways. However, the role of long non-coding RNAs (lncRNAs), a class of crucial epigenetic regulatory molecules, has been under explored in skeletal biology. RESULTS: Here we report a young patient with short stature, hypothalamic dysfunction and mild macrocephaly, who carries a maternally inherited 690 kb deletion at Chr.1q24.2 encompassing a noncoding RNA gene, DNM3OS, embedded on the opposite strand in an intron of the DYNAMIN 3 (DNM3) gene. We show that lncRNA DNM3OS sustains the proliferation of chondrocytes independent of two co-cistronic microRNAs miR-199a and miR-214. We further show that nerve growth factor (NGF), a known factor of chondrocyte growth, is a key target of DNM3OS-mediated control of chondrocyte proliferation. CONCLUSIONS: This work demonstrates that DNM3OS is essential for preventing premature differentiation of chondrocytes required for bone growth through endochondral ossification.

Delineation of the 1q24.3 microdeletion syndrome provides further evidence for the potential role of non-coding RNAs in regulating the skeletal phenotype.

Microdeletions within 1q24 have been associated with growth deficiency, varying intellectual disability, and skeletal abnormalities. The candidate locus responsible for the various phenotypic features of this syndrome has previously been predicted to lie in the area of 1q24.3, but molecular evidence of the causative gene remains elusive. Here, we report two additional patients carrying the smallest reported 1q24 deletion to date. Patient 1 exhibited intrauterine growth retardation, shortening of the long bones, frontal bossing, microstomia, micrognathia, and a language acquisition delay. Her mother, Patient 2, displayed a broad forehead and nasal bridge, thick supraorbital ridges, and toe brachydactyly, along with learning disability and language acquisition delay. The microdeletion encompasses a 94 Kb region containing exon 14 and portions of the surrounding introns of the gene encoding dynamin 3 (DNM3), resulting in an in-frame loss of 38 amino acids. This microdeletion site also contains a long non-coding RNA (DNM3OS) and three microRNAs (miR-214, miR-199A2, and miR-3120). Following culture of patient-derived and control fibroblasts, molecular analyses were performed to determine expression levels of genes affected by the heterozygous deletion. Results show decreased expression of DNM3OS and miR-214-3p in patient fibroblasts cultured in an osteogenic induction medium. Overall, our data provide further evidence to support a functional role for non-coding RNAs in regulating the skeletal phenotype, and the potential of a functionally-impaired DNM3 protein causing the non-skeletal disease pathogenesis.

1q24 deletion syndrome. Two cases and new insights into genotype-phenotype correlations.

1q24q25 deletions cause a distinctive phenotype including proportionate short stature, microcephaly, brachydactyly, dysmorphic facial features and intellectual disability. We present a mother and son who have a 672 kb microdeletion at 1q24q25. They have the typical skeletal features previously described but do not have any associated intellectual disability. We compare the genes within our patients' deletion to those in the deletions of previously reported cases. This indicates two genes that may be implicated in the intellectual disability usually associated with this deletion syndrome; PIGC and C1orf105. In addition, our cases provide supporting evidence to recent published work suggesting that the skeletal features may be linked to the microRNAs miR199 and miR214, encoded within intron 14 of the Dynamin-3 gene.

Hearing impairment in a female infant with interstitial deletion of 2q24.1q24.3.

Patients with interstitial deletions in 2q24.1q24.3 are rarely reported. These patients manifest a variety of clinical features in addition to intellectual disability, depending on the size and location of the deletion. We report a female patient with interstitial deletion of 5.5 Mb in 2q24.1q24.3, who showed intrauterine growth retardation, hypotonia, global developmental delay, microcephaly, and characteristic facial appearance. In addition, she had hearing impairment, with no auditory brainstem response. Case of 2q24.1q24.3 deletion with hearing impairment is quite rare. We suspect that hearing impairment is caused by bilateral cochlear nerve deficiency due to cochlear nerve canal stenosis. Further studies are necessary to evaluate hearing impairment as a clinical feature in patients with de novo heterozygous 2q24.1q24.3 deletion.

Two further patients with the 1q24 deletion syndrome expand the phenotype: A possible role for the miR199-214 cluster in the skeletal features of the condition.

Submicroscopic deletions within chromosome 1q24q25 are associated with a syndromic phenotype of short stature, brachydactyly, learning difficulties, and facial dysmorphism. The critical region for the deletion phenotype has previously been narrowed to a 1.9 Mb segment containing 13 genes. We describe two further patients with 1q24 microdeletions and the skeletal phenotype, the first of whom has normal intellect, whereas the second has only mild learning impairment. The deletion in the first patient is very small and further narrows the critical interval for the striking skeletal aspects of this condition to a region containing only Dynamin 3 (DNM3) and two microRNAs that are harbored within intron 14 of this gene: miR199 and miR214. Mouse studies raise the possibility that these microRNAs may be implicated in the short stature and skeletal abnormalities of this microdeletion condition. The deletion in the second patient spans the previously reported critical region and indicates that the cognitive impairment may not always be as severe as previous reports suggest.

Refinement of genotype-phenotype correlation in 18 patients carrying a 1q24q25 deletion.

Interstitial deletion 1q24q25 is a rare rearrangement associated with intellectual disability, growth retardation, abnormal extremities and facial dysmorphism. In this study, we describe the largest series reported to date, including 18 patients (4M/14F) aged from 2 days to 67 years and comprising two familial cases. The patients presented with a characteristic phenotype including mild to moderate intellectual disability (100%), intrauterine (92%) and postnatal (94%) growth retardation, microcephaly (77%), short hands and feet (83%), brachydactyly (70%), fifth finger clinodactyly (78%) and facial dysmorphism with a bulbous nose (72%), abnormal ears (67%) and micrognathia (56%). Other findings were abnormal palate (50%), single transverse palmar crease (53%), renal (38%), cardiac (38%), and genital (23%) malformations. The deletions were characterized by chromosome microarray. They were of different sizes (490 kb to 20.95 Mb) localized within chromosome bands 1q23.3-q31.2 (chr1:160797550-192912120, hg19). The 490 kb deletion is the smallest deletion reported to date associated with this phenotype. We delineated three regions that may contribute to the phenotype: a proximal one (chr1:164,501,003-167,022,133), associated with cardiac and renal anomalies, a distal one (chr1:178,514,910-181,269,712) and an intermediate 490 kb region (chr1:171970575-172460683, hg19), deleted in the most of the patients, and containing DNM3, MIR3120 and MIR214 that may play an important role in the phenotype. However, this genetic region seems complex with multiple regions giving rise to the same phenotype.

Phenotypic and genetic characterization of a patient with a de novo interstitial 14q24.1q24.3 deletion.

BACKGROUND: Interstitial deletions of chromosome bands 14q24.1q24.3 are very rare with only three reported cases. RESULTS: We describe a 7-year-old boy with a 5.345 Mb de novo interstitial deletion at 14q24.1q24.3 band detected by array-CGH who had a complex phenotype characterized by seizures, congenital heart defects, dysmorphisms, psychomotor delay, and bronchopulmonary, skeletal, and brain anomalies. CONCLUSION: The deleted region contains numerous genes, but we focused our attention on three of them (C14orf169, NUMB, and PSEN1), which could account, at least partially, for the phenotype of the boy. We therefore discuss the involvement of these genes and the observed phenotype compared to that of previously described patients.

The first case of a patient with de novo partial distal 16q tetrasomy and a data's review.

We report on a patient with severe psychomotor disability, numerous dysmorphic features, and congenital malformations resulting from a complex genomic rearrangement on 16q24.1-q24.3 involving a de novo duplication-triplication pattern. To the best of our knowledge, this is the first reported patient presenting with this aberration within the distal chromosome 16q. We suggest that the clinical phenotype of our patient results from over-dosage of genes mapped to the region with duplication/triplication (five genes: FOXF1, FOXC2, ANKRD11, SPG7 and FANCA seem to play a peculiar role). Detailed molecular characterization and documentation of the complex genomic rearrangement observed in the proband and of the clinical presentation are important for accurate genotype-phenotype correlations in genetic counseling. Delineation of the gene map for the terminal region of chromosome 16q will provide insight into this chromosome 16q24.1-q24.3 contiguous gene duplication-triplication syndrome.

Deletions in 14q24.1q24.3 are associated with congenital heart defects, brachydactyly, and mild intellectual disability.

Interstitial deletions of chromosome band 14q24.1q24.3 are apparently very rare. We report on three unrelated patients with overlapping de novo deletions of sizes 5.4, 2.8, and 2.3 Mb in this region. While some clinical problems such as intestinal malrotation, cryptorchidism, and ectopic kidney were only observed in single patients, all three patients had mild intellectual disability, congenital heart defects (truncus arteriosus, pulmonary atresia, atrial septal defect, and/or ventricular septal defect), brachydactyly, hypertelorism, broad nasal bridge, and thin upper lips. Likely haploinsufficiency of one or several of the 19 genes in the common deleted interval (ACTN1, DCAF5, EXD2, GALNTL1, ERH, SLC39A9, PLEKHD1, CCDC177, KIAA0247, LOC100289511, SRSF5, SLC10A1, SMOC1, SLC8A3, ADAM21P1, COX16, SYNJ2BP, SYNJ2BP-COX16, ADAM21) was responsible for these manifestations, but apart from SMOC1, mutations in which cause autosomal recessive Waardenburg anophthalmia syndrome, and ACTN1, mutations in which are associated with congenital macrothrombocytopenia, no disease associations have so far been reported for the other genes. Functional studies and a systematic search for mutations or chromosome aberrations in this region will elucidate the role of individual genes in the clinical manifestations and will provide insight into the underlying biological mechanisms.

Pituitary deficiency and congenital infiltrating lipomatosis of the face in a girl with deletion of chromosome 1q24.3q31.1.

Interstitial deletions of the long arm of chromosome 1 are rare and they are classified as proximal or intermediate. The intermediate interstitial deletions span 1q24-1q32. We describe a 6-year-old girl with multiple pituitary hormone deficiency, severe cognitive impairment, bilateral cleft lip and palate, midline facial capillary malformation, erythema of hands and feet and dysplastic cranial vessels, low anti-thrombin III activity, hemifacial overgrowth due to progressive infiltrating lipomatosis with bone overgrowth, marked vascular proliferation and erythema of hands and feet, and abnormal cranial vessels. The girl's karyotype showed an apparently de novo interstitial deletion 1q24.3q31.1, which was defined by array-CGH. The deleted region contains numerous genes, but only eight (CENPL, LHX4, LAMC1, LAMC2, PTGS2, ANGPTL1, TNN, and TNR) are good candidates to explain, at least partially, the phenotype of the proposita. We, therefore, discuss the involvement of these genes and the observed phenotype.