Divergent variant patterns among 19 patients with Rubinstein-Taybi syndrome uncovered by comprehensive genetic analysis including whole genome sequencing.

Rubinstein-Taybi syndrome (RSTS) is characterized by dysmorphic facial features, broad thumbs, and intellectual disability. CREB-binding protein (CREBBP) or E1A-binding protein P300 (EP300) are causative genes. To elucidate the underlying genetic and genomic architecture related to the RSTS phenotype, we performed comprehensive genetic analysis targeting CREBBP and/or EP300 in 22 clinically diagnosed patients. During the 11-year study period, we used several analysis methods including high-resolution melting, array-based comparative genomic hybridization, panel-based exome sequencing, whole exome sequencing, and whole genome sequencing (WGS). We identified the causative variants in 19 patients (86.3%), but they were variable and complex, so we must combine multiple analysis methods. Notably, we found genetic alterations in the non-coding regions of two patients (10.5%, 2/19): scattered deletions including a partial 5'-untranslated region of CREBBP in one patient (all coding exons were intact), and a deep 229-bp intronic deletion in another patient, resulting in a splicing error. Furthermore, we identified rare clinical findings: two patients with an EP300 variant showed abnormal development of the neural tube, and one patient with a CREBBP variant had anorectal atresia with a cloaca. Our findings expand the allelic heterogeneity of RSTS, underscore the utility of comprehensive genetic analysis, and suggest that WGS may be a practical diagnostic strategy.

Update of the genotype and phenotype of KMT2D and KDM6A by genetic screening of 100 patients with clinically suspected Kabuki syndrome.

Kabuki syndrome is characterized by a variable degree of intellectual disability, characteristic facial features, and complications in various organs. Many variants have been identified in two causative genes, that is, lysine methyltransferase 2D (KMT2D) and lysine demethylase 6A (KDM6A). In this study, we present the results of genetic screening of 100 patients with a suspected diagnosis of Kabuki syndrome in our center from July 2010 to June 2018. We identified 76 variants (43 novel) in KMT2D and 4 variants (3 novel) in KDM6A as pathogenic or likely pathogenic. Rare variants included a deep splicing variant (c.14000-8C>G) confirmed by RNA sequencing and an 18% mosaicism level for a KMT2D mutation. We also characterized a case with a blended phenotype consisting of Kabuki syndrome, osteogenesis imperfecta, and 16p13.11 microdeletion. We summarized the clinical phenotypes of 44 patients including a patient who developed cervical cancer of unknown origin at 16 years of age. This study presents important details of patients with Kabuki syndrome including rare clinical cases and expands our genetic understanding of this syndrome, which will help clinicians and researchers better manage and understand patients with Kabuki syndrome they may encounter.

A severe form of Ellis-van Creveld syndrome caused by novel mutations in EVC2.

Ellis-van Creveld syndrome (EvC MIM. #225500) is an autosomal recessive skeletal dysplasia characterised by thoracic hypoplasia, cardiac anomalies, acromesomelic limb shortening, and postaxial polydactyly. Affected individuals commonly manifest with cardiorespiratory failure as neonates but generally survive neonatal difficulties. We report here on affected Japanese sibs with a lethal phenotype of EvC caused by novel compound heterozygous mutations of EVC2, c.871-3 C > G and c.1991dupA.

Familial total anomalous pulmonary venous return with 15q11.2 (BP1-BP2) microdeletion.

A 15q11.2 microdeletion (BP1-BP2) is associated with congenital heart diseases (CHDs), developmental delay, and epilepsy. This deletion co-occurs with CHD in 20-30% patients, but a familial case of CHD and a 15q11.2 deletion has not been identified. Here we report the first familial (three siblings) case of total anomalous pulmonary venous return associated with 15q11.2 deletion. Array comparative genomic hybridization identified a ~395 kb deletion at 15q11.2 in patient 1. This deletion was confirmed by fluorescence in situ hybridization in patients 1 and 3 and their asymptomatic father. No deleterious mutation was identified by proband-only exome sequencing of patient 1. One healthy sibling and their mother did not carry the deletion. This deletion is often inherited from asymptomatic parents with an estimated low penetrance of 10.4%. Conversely, we observed high penetrance of this deletion, but secondary copy-number variants or pathogenic variants were not detected in this family.

Evaluation of a patient with classical Ehlers-Danlos syndrome due to a 9q34 duplication affecting COL5A1.

Ehlers-Danlos syndrome classical type is a connective tissue disorder characterized by skin hyperextensibility, atrophic scarring, and joint hypermobility. The condition typically results from mutations in COL5A1 or COL5A2 leading to the functional haploinsufficiency. Here, we report of a 24-year-old male with mild intellectual disability, dysmorphic features, and a phenotype consistent with Ehlers-Danlos syndrome classical type. A copy number variant-calling algorithm from panel sequencing data identified the deletions exons 2-11 and duplications of exons 12-67 within COL5A1. Array comparative genomic hybridization confirmed a 94 kb deletion at 9q34.3 involving exons 2-11 of COL5A1, and a 3.4 Mb duplication at 9q34.3 involving exons 12-67 of COL5A1.

Repeated collection of conjoined oocytes from a patient with polycystic ovary syndrome, resulting in one successful live birth from frozen thawed blastocyst transfer: a case report.

Few cases have been reported in which the aspiration of a single follicle led to the recovery of two conjoined oocytes surrounded by a single zona pellucida. This report describes a successful embryo transfer with subsequent live birth derived from conjoined oocytes, and a later pair of conjoined oocytes in the same patient. After oocyte retrieval from a patient with polycystic ovary syndrome, two pairs of conjoined oocytes were collected. One oocyte was fertilized using in vitro fertilization (IVF) and developed to the blastocyst stage. This blastocyst was cryopreserved and later transferred to the uterus after separating the unfertilized conjoined oocyte. A successful pregnancy and healthy live birth was achieved. Two years later, the patient returned for a second IVF; one pair of conjoined oocytes was detected. One of the pair was fertilized and developed to a blastocyst, but was not transferred. We demonstrate that selective fertilization of a mature oocyte from conjoined oocytes by IVF can lead to the development of a blastocyst and subsequent pregnancy and live birth. To our knowledge, this is the second case report of successful live birth from conjoined oocytes. It may be the first case of repeated fertile conjoined oocytes from the same patient.

A novel UBE2A mutation causes X-linked intellectual disability type Nascimento.

X-linked intellectual disability (ID) type Nascimento (MIM #300860), also known as ubiquitin-conjugating enzyme E2 A (UBE2A) deficiency syndrome, is a congenital malformation syndrome characterized by moderate to severe ID, speech impairment, dysmorphic facial features, genital anomalies and skin abnormalities. Here, we report a Japanese patient with severe ID and congenital cataract. We identified a novel hemizygous mutation (c.76G>A, p.Gly26Arg) in UBE2A by whole-exome sequencing.

Delineation of the KIAA2022 mutation phenotype: two patients with X-linked intellectual disability and distinctive features.

Next-generation sequencing has enabled the screening for a causative mutation in X-linked intellectual disability (XLID). We identified KIAA2022 mutations in two unrelated male patients by targeted sequencing. We selected 13 Japanese male patients with severe intellectual disability (ID), including four sibling patients and nine sporadic patients. Two of thirteen had a KIAA2022 mutation. Patient 1 was a 3-year-old boy. He had severe ID with autistic behavior and hypotonia. Patient 2 was a 5-year-old boy. He also had severe ID with autistic behavior, hypotonia, central hypothyroidism, and steroid-dependent nephrotic syndrome. Both patients revealed consistent distinctive features, including upswept hair, narrow forehead, downslanting eyebrows, wide palpebral fissures, long nose, hypoplastic alae nasi, open mouth, and large ears. De novo KIAA2022 mutations (p.Q705X in Patient 1, p.R322X in Patient 2) were detected by targeted sequencing and confirmed by Sanger sequencing. KIAA2022 mutations and alterations have been reported in only four families with nonsyndromic ID and epilepsy. KIAA2022 is highly expressed in the fetal and adult brain and plays a crucial role in neuronal development. These additional patients support the evidence that KIAA2022 is a causative gene for XLID.

West syndrome in a patient with Schinzel-Giedion syndrome.

Schinzel-Giedion syndrome is a rare recognizable malformation syndrome defined by characteristic facial features, profound developmental delay, severe growth failure, and multiple congenital anomalies. The causative gene of Schinzel-Giedion syndrome, SETBP1, has been identified, but limited cases have been confirmed by molecular analysis. We present a 9-month-old girl affected by West syndrome with Schinzel-Giedion syndrome. Congenital severe hydronephrosis, typical facial features, and multiple anomalies suggested a clinical diagnosis of Schinzel-Giedion syndrome. Hypsarrhythmia occurred at 7 months of age and was temporarily controlled by adrenocorticotropic hormone (ACTH) therapy during 5 weeks. SETBP1 mutational analysis showed the presence of a recurrent mutation, p.Ile871Thr. The implications in management of Schinzel-Giedion syndrome are discussed.

Deletion of UBE3A in brothers with Angelman syndrome at the breakpoint with an inversion at 15q11.2.

Angelman syndrome (AS) is characterized by severe intellectual disability with ataxia, epilepsy, and behavioral uniqueness. The underlining molecular deficit is the absence of the maternal copy of the imprinted UBE3A gene due to maternal deletions, which is observed in 70-75% of cases, and can be detected using fluorescent in situ hybridization (FISH) of the UBE3A region. Only a few familial AS cases have been reported with a complete deletion of UBE3A. Here, we report on siblings with AS caused by a microdeletion of 15q11.2-q12 encompassing UBE3A at the breakpoint of an inversion at 15q11.2 and 15q26.1. Karyotyping revealed an inversion of 15q, and FISH revealed the deletion of the UBE3A region. Array comparative genomic hybridization (CGH) demonstrated a 467 kb deletion at 15q11.2-q12, encompassing only UBE3A, SNORD115, and PAR1, and a 53 kb deletion at 15q26.1, encompassing a part of SLCO3A1. Their mother had a normal karyotype and array CGH detected no deletion of 15q11.2-q12, so we assumed gonadal mosaicism. This report describes a rare type of familial AS detected using the D15S10 FISH test.

Refinement of the deletion in 8q22.2-q22.3: the minimum deletion size at 8q22.3 related to intellectual disability and epilepsy.

Kuechler et al. [2011] reported five patients with interstitial deletions in 8q22.2-q22.3 who had intellectual disability, epilepsy, and dysmorphic features. We report on a new patient with the smallest overlapping de novo deletion in 8q22.3 and refined the phenotype. The proposita was an 8-year-old girl, who developed seizures at 10 months, and her epileptic seizure became severe and difficult to control with antiepileptic drugs. She also exhibited developmental delay and walked alone at 24 months. She was referred to us for evaluation for developmental delay and epilepsy at the age of 8 years. She had intellectual disability (IQ 37 at 7 years) and autistic behavior, and spoke two word sentences at 8 years. She had mild dysmorphic features, including telecanthus and thick vermilion of the lips. Array comparative genomic hybridization detected a 1.36 Mb deletion in 8q22.3 that encompassed RRM2B and NCALD, which encode the small subunit of p53-inducible ribonucleotide reductase and neurocalcin delta in the neuronal calcium sensor family of calcium-binding proteins, respectively. The minimum overlapping region between the present and previously reported patients is considered to be a critical region for the phenotype of the deletion in 8q22.3. We suggest that the deletion in 8q22.3 may represent a clinically recognizable condition, which is characterized by intellectual disability and epilepsy.

De novo duplication of 17p13.1-p13.2 in a patient with intellectual disability and obesity.

17p13.1 Deletion encompassing TP53 has been described as a syndrome characterized by intellectual disability and dysmorphic features. Only one case with a 17p13.1 duplication encompassing TP53 has been reported in a patient with intellectual disability, seizures, obesity, and diabetes mellitus. Here, we present a patient with a 17p13.1 duplication who exhibited obesity and intellectual disability, similar to the previous report. The 9-year-old proposita was referred for the evaluation of intellectual disability and obesity. She also exhibited insulin resistance and liver dysfunction. She had wide palpebral fissures, upturned nostrils, a long mandible, short and slender fingers, and skin hyperpigmentation. Array comparative genomic hybridization (array CGH) detected a 3.2 Mb duplication of 17p13.1-p13.2 encompassing TP53, FXR2, NLGN2, and SLC2A4, which encodes the insulin-responsive glucose transporter 4 (GLUT4) associated with insulin-stimulated glucose uptake in adipocytes and muscle. We suggest that 17p13.1 duplication may represent a clinically recognizable condition characterized partially by a characteristic facial phenotype, developmental delay, and obesity.

Two families with compound heterozygosity for adenine phosphoribosyltransferase deficiency.

Adenine phosphoribosyltransferase deficiency is a disorder in which 2,8-dihydroxyadenine (2,8-DHA) crystalluria is caused by a congenital deficiency in the enzyme adenine phosphoribosyltransferase (APRT). In most cases, APRT deficiency is caused by autosomal recessive inheritance of a homozygote of the mutant gene APRT*Q0 or APRT*J, but there are also some cases in which the disorder is caused by the compound heterozygote APRT*Q0 and APRT*J. In the patients described here, brown round crystals were found in their urinary sediment. Crystalluria was the first sign of APRT deficiency, thereafter confirmed by genetic screening for APRT*/Q0 and APRT*. We performed genetic screening for APRT*Q0 and APRT*J in two families and diagnosed three cases of APRT*Q0 /APRT*J compound heterozygote-type APRT deficiency. Genetic screening for APRT*Q0 and APRT*J of family members is effective for early diagnosis and early treatment for family members.

Chemical zona pellucida thinning with acidified Tyrode's solution: comparison between partial and circumferential techniques.

PURPOSE: To compare effectiveness of two different chemical zona thinning techniques. METHOD: We studied 163 patients who had experienced IVF or ICSI failures in two or more cycles. Patients were assigned to one of three groups: zona intact (n=72), partial thinning (n=59), or circumferential thinning (n=73). Before transfer, the zonae pellucidae of embryos were thinned partially or circumferentially using acidified Tyrode's solution. RESULTS: Implantation rates were 8.9% in the intact zona group, 17.6% in the partial thinning group, and 11.9% in the circumferential thinning group: respective clinical pregnancy rates were 16.7% (12/72), 32.2% (19/59), and 27.4% (20/73). Both rates were significantly higher in the partial thinning group than the intact zona group. For circumferential thinning versus zona intact groups, differences fell short of significance. CONCLUSIONS: Following embryo transfer failure, partial thinning would be recommended over circumferential thinning for successful assisted hatching.

Assisted hatching using a 1.48-µm diode laser: Evaluation of zona opening and zona thinning techniques in human embryos.

Aim: We assessed the effectiveness of assisted hatching using a 1.48-µm diode laser in human embryos, comparing zona opening and zona thinning techniques. Methods: A total of 56 day 3 embryos were assigned randomly to a zona opening group, a zona thinning group, or a control group. We then carried out assisted hatching using the OCTAX Laser Shot system (MTG Medical Technology, Altdorf, Germany) in the first two groups. In the zona opening group, the inner membrane of the zona pellucida was broken to create a full-thickness opening. In the zona thinning group, the inner membrane of the zona pellucida was not breached. After the laser procedure, embryos were cultured to the hatched blastocyst stage. Results: Blastocyst development rates did not differ significantly between the three groups. In the zona opening group, blastocysts were significantly more likely to hatch than those in the control group (P ≤ 0.05) and no arrested hatching of blastocysts was observed. Conclusions: Assisted hatching using a 1.48-µm diode laser in the zona opening technique increases the likelihood of blastocyst hatching in human embryos and does not adversely effect subsequent embryo development. (Reprod Med Biol 2006; 5: 221-226).