6p subtelomere deletion with congenital glaucoma,severe mental retardation,and growth impairment

Submicroscopic deletion of the 6p subtelomere has recently been recognized as a clinically identifiable syndrome. A distinct phenotype has emerged consisting of developmental delay/mental retardation, language impairment, hearing loss, and ophthalmologic, cardiac, and craniofacial abnormalities, including hypertelorism, midface hypoplasia, small nose, and high arched palate. We describe here a patient with 6p subtelomere deletion associated with congenital glaucoma, severe mental retardation, and growth impairment. Fluorescent in situ hybridization analysis revealed only one 6p25.3 signal. Array comparative genomic hybridization assay showed 2.1 Mb deletion and 4.14 Mb duplication in the 6p25 region. Generally, developmental delay and language impairment are common findings in patients with 6p subtelomere deletion syndrome, but growth impairment is not. Compared to that, the present patient showed atypically severe developmental delay and growth impairment.     

A Say‐Barber‐Biesecker‐Young‐Simpson variant of Ohdo syndrome with a KAT6B 10‐base pair palindromic duplication: A recurrent mutation causing a severe phenotype mixed with genitopatellar syndrome

The Say‐Barber‐Biesecker‐Young‐Simpson variant of Ohdo syndrome (SBBYSS) (MIM# 603736) and genitopatellar syndrome (GPS) (MIM#606170) are allelic diseases caused by KAT6B mutation. Genotype–phenotype correlation is assumed, but a few patients manifest overlapping features of both syndromes. Here we report the case of a boy with SBBYSS. He had a KAT6B mutation previously reported in typical SBBYSS, but he also manifested severe developmental delay, as well as genital features and laryngomalacia requiring tracheostomy that conformed to GPS.     

15q11.2-13.2微重复四倍体综合征1例并文献复习

目的 采用分子遗传学技术分析1例常规染色体核型拟诊为21/22三体的发育迟缓伴孤独症患儿,明确遗传学诊断。方法 收集患儿及其父母的外周血标本,常规提取基因组DNA,应用高分辨染色体核型分析（400-550带）检测患儿及其父母的染色体数目及结构,微阵列比较基因组杂交技术(array-CGH)筛查患儿的全基因组拷贝数变异,以荧光原位杂交技术（FISH）对异常的基因拷贝进行染色体精确定位和定量。结果 女,2岁,发育迟缓伴孤独症样表现。外侧眼角下垂、内眦赘皮。常规染色体核型检查（320带）分别为47,XX,+22和47,XX,+21。高分辨染色体核型分析显示,该患儿携带额外标记染色体（SMC）,核型为47,XX,+mar dn,尚不能确定是否为21/22三体携带者,患儿父亲高分辨率核型染色体分析提示为46,XY,母亲为46,XX,提示患儿携带SMC为新生突变。array-CGH检测显示15q11.2-13.2区域微重复（chr15:22684529-30730543,8.0 Mb,hg19）。FISH验证该SMC来源于15号染色体,由15q11.2-13.2区域二倍体及双着丝粒组成。患儿最终诊断为15q11.2-13.2微重复四倍体综合征。复习文献报道的15q11.2-13.2拷贝数增加病例的临床表型,微重复四倍体综合征的主要表型有智力低下/发育迟缓（100％）、肌张力低下（92.9％）、孤独症/孤独症样表现（71.4％）和癫痫（61.5％）等。结论 15q11.2-13.2微重复四倍体综合征是患儿发生精神发育迟滞伴孤独症的遗传学基础,array-CGH能够快速、准确地检测基因组的微小失衡。     

Sotos综合征的临床表型及遗传学分析

3例男性患儿,年龄7~13个月,均以运动发育迟缓、智力落后就诊,均有前额突出、眼距宽或者下颌尖长等特殊面容,身长和头围方面仅病例1的头围超过2 SD,其中2例患儿的骨龄超前、1例患儿脑电图异常,3例患儿头部CT均显示脑室扩大。全基因组芯片分析发现1例患儿染色体5q35.2区域缺失一个1.75 Mb大小的拷贝,其中包括NSD1基因;荧光定量PCR方法对拷贝数异常区域进行验证：NSD1基因拷贝数减半。高通量测序分析发现另2例患儿的NSD1基因分别存在c.1157T > G杂合突变和c.1177G > T杂合突变,其中c.1157T > G杂合突变未见报道,但生物信息学分析提示该位点突变具有致病性。因此,3例患儿均确诊为Sotos综合征。Sotos综合征是常染色体显性遗传的先天性生长过度症,70%~90%的患者存在NSD1基因突变,约10%存在染色体5q35区域（包括NSD1基因）缺失。     

Phenotype profiling of patients with intellectual disability and copy number variations

BackgroundNowadays the microarray technology allows whole-genome analysis with a high resolution and performance for the genetic diagnosis in any patient with intellectual disability or autism spectrum disorder. However in the immediate future, with the development of massive sequencing systems for application at clinical diagnosis, it will be necessary to have clinical criteria to guide studies.AimTo perform an exhaustive clinical definition of patients with pathogenic copy number variations in order to establish the clinical criteria most suggestive of this kind of genomic rearrangements.MethodWe designed and implemented a database to collect 190 different clinical variables (pregnancy, neonatal, facial dysmorphism, congenital anomalies, neurological features and family history) in a series of 246 patients, with developmental delay/intellectual disability. All cases were studied with array comparative genomic hybridization.ResultsWe have found a pathogenic genomic imbalance in 73 patients. Frequency analysis of all clinical variables showed that growth disorder, abnormalities of hands, low-set ears and hypertelorism are the more frequent features among patients with genomic rearrangements. However other clinical features, such as genital abnormalities and aggressiveness, are more specifically associated with pathogenic copy number variations in spite of their low frequencies in the overall series, yielding higher statistical significance values than other traits.ConclusionsThe genotype–phenotype comparison may be useful to set in the future the main clinical manifestations associated with deletions, duplications and unbalanced translocations. Theses analyses will improve the clinical indications and protocols to implement genomic arrays in the genetic study of patients with neurodevelopment disorders.     

微阵列比较基因组杂交技术对不明原因智力低下/生长发育迟缓患儿的分子诊断

目的　分析不明原因智力低下(ID)和(或)生长发育迟缓(DD)患儿潜在的致病性基因组不平衡, 及其与表型的相关性, 探讨高密度微阵列比较基因组杂交技术(array-CGH)在临床分子遗传学诊断中的应用价值。方法　采用array-CGH技术对16例ID/DD患儿进行全基因组扫描分析, 并用多重连接探针扩增技术(MLPA)对检出的基因组不平衡异位进行验证。结果　16例患儿高分辨G显带核型分析均无异常。6例(38%)患儿存在基因拷贝数异常(CNVs), 其中3例CNVs为正常多态性改变; 1例CNVs涉及4p16.3区域微缺失, 考虑为Wolf-Hirschhorn综合征; 1例CNVs涉及7q11.23区域微缺失, 考虑为Williams-Beuren 综合征; 另1例CNVs临床意义不明确, 包含2个重复突变, 该突变与智力低下、脑发育迟缓、特殊面容、隐睾、牙列不齐等有关, 证实该CNVs具有临床意义。结论 通过array-CGH技术对不明原因ID/DD患儿进行全基因组扫描, 可为部分患儿明确病因诊断。该技术作为一种高通量、快速的疾病研究手段, 在ID/DD的病因诊断中具有重要的临床意义。     

A further case of the recurrent 15q24 microdeletion syndrome,detected by array CGH

We report on a 10-year-old patient with developmental delay, craniofacial dysmorphism, digital and genital abnormalities. In addition, muscular hypotonia, strabism, and splenomegaly were observed; inguinal and umbilical hernias were surgically corrected. Mucopolysaccharidoses and CDG syndromes could not be found. Chromosome analysis revealed a normal male karyotype (46,XY). A more detailed investigation of the patient's genomic DNA by microarray-based comparative genomic hybridization (array CGH) detected an interstitial 3.7 Mb deletion ranging from 15q24.1 to 15q24.3 which was shown to be de novo. Interstitial deletions involving 15q24 are rare. Sharp et al. (Hum Mol Genet 16:567-572, 2007) recently characterized a recurrent 15q24 microdeletion syndrome with breakpoints in regions of segmental duplications. The de novo microdeletion described here colocalizes with the minimal deletion region of the 15q24 microdeletion syndrome. The distinct clinical phenotype associated with this novel microdeletion syndrome is similar to the phenotype of our patient with respect to specific facial features, developmental delay, microcephaly, digital abnormalities, and genital abnormalities in males. We present a genotype-phenotype correlation and comparison with patients from the literature.     

Association of ABCC2 with levels and toxicity of methotrexate in Malaysian Childhood Acute Lymphoblastic Leukemia (ALL)

Abstract

Studies had shown that genetic polymorphism plays a significant role in the pharmacokinetics and pharmacodynamics variation of high dose methotrexate (MTX), 5000?mg/m² regimen. The objective of this study was to investigate the genetic variations associated with the serum level and toxicity of MTX in Malaysian children with acute lymphoblastic leukemia (ALL). Thirty-eight patients were genotyped for rs717620 (ABCC2), rs4948496 (ARID5B), rs1801133 (MTHFR) and rs4149056 (SLCO1B1). Serum levels of MTX at 48?h post 24?h of intravenous infusion were analyzed by high-performance liquid chromatography-mass spectrometry. The ABCC2 genotype was significantly associated with the serum levels of MTX at 48?h after treatment (p?=?0.017). Patients with CT and TT of rs717620 (ABCC2) and TC and CC of rs4948496 (ARID5B) were significantly associated with leukopenia grade I–IV (Fisher Exact Test; p?=?0.03 and 0.02, respectively). The three most common MTX related toxicities were leukopenia (60.5%), increased alanine aminotransferase enzyme (47.4%), and thrombocytopenia (47.4%). Our results demonstrate that by prescreening of patients for ABCC2 and ARID5B associated with the serum levels and adverse effects of MTX would identify patients at risk and therefore help a pediatric oncologist to personalize chemotherapy drugs for precision health.     

Worster-Drought syndrome (congenital bilateral perisylvian syndrome) with posterior pituitary ectopia, pituitary hypoplasia, empty sella and panhypopituitarism: a patient report

Worster-Drought syndrome (WDS) (congenital bilateral perisylvian syndrome, congenital pseudobulbar paresia) is characterized by neuronal migration defect, pseudobulbar paralysis, epilepsy, neuromotor retardation and perisylvian dysplasia. We report a patient with WDS associated with posterior pituitary ectopia, pituitary hypoplasia, partial empty sella and panhypopituitarism, not previously reported in the literature. The 16.4 year-old female patient had severe growth retardation with height SDS -4.5, delayed puberty, microcephaly, pes equinovarus deformity, developmental delay, speech disorder and epilepsy. Laboratory findings, which revealed abnormal electroencephalography and bilateral perisylvian cortical dysplasia on cranial magnetic resonance imaging (MRI) were consistent with WDS. Endocrinological evaluation revealed secondary hypothyroidism and combined deficiency of adrenocorticotropin, gonadotropin and growth hormone (GH). Sella MRI showed congenital empty sella, anterior pituitary hypoplasia, ectopic neurohypophysis, and stalk agenesis. Appropriate replacement therapy was started. GH treatment resulted in a final height of 150.3 cm, appropriate for her target height. This is the first reported patient with WDS associated with congenital structural hypothalamic-pituitary abnormalities, including empty sella, pituitary hypoplasia, posterior pituitary ectopia, stalk agenesis and panhypopituitarism. GH has been successful in the treatment of her short stature.     

Clinical and genetic characteristics and effects of long-term growth hormone therapy in a girl with Floating-Harbor syndrome

The established facts to date relating to Floating-Harbor syndrome (FHS) are its characteristic typical triangular facies with bulbous nose and thin lips, short stature, delayed bone age, and mild mental retardation with delay in expressive speech; its sporadic occurrence without Mendelian inheritance; and its unknown cause. Little is known about the growth hormone-insulin-like growth factor 1 (GH-IGF-1) axis and the effect of GH treatment in children with this syndrome. We report on a 9-year-old girl born small for gestational age (SGA, birth length -2.2 standard deviation score) with persistent short stature who has been treated with GH from 3.5 years onward with a modest growth response. Revision of the case led to the diagnosis of FHS. No abnormalities were found in the sequence or copy number of IGF-1 receptor or in the genomic single-nucleotide polymorphism array. GH treatment led to an increase in serum IGF-1 in the upper normal range, but the growth response was modest, suggesting a defect in IGF-1 signaling. Early recognition of this entity is important, as it enables specific diagnostic tests targeted at other abnormalities associated with FHS.     

Desbuquois syndrome: clinical and radiological report of the first two Chinese cases from a consanguineous family

Abstract:   Two siblings from China have been observed with severe short stature of prenatal onset and developmental delay. The radiographic features were characteristic of Desbuquois syndrome. The association of a genetic skeletal dysplasia and developmental delay is a relatively rare combination, although this syndrome is readily diagnosable from its distinctive radiographic features.     

16q12 microdeletion syndrome in two Japanese boys

Microdeletion of 16q12 is a rare chromosomal abnormality. We present the cases of two Japanese patients with developmental and renal symptoms of differing clinical severity. Both patients had 16q12 interstitial microdeletions that included the entire SALL1 gene. Patient 1 was a 15‐year‐old Japanese boy clinically diagnosed with branchio‐oto‐renal syndrome with mild developmental delay, but with no imperforate anus or polydactyly. Array comparative genome hybridization (aCGH) indicated a 5.2 Mb deletion in 16q12, which included SALL1. Patient 2 was a 13‐year‐old Japanese boy diagnosed with Townes–Brocks syndrome and severe developmental delay, epilepsy, and renal insufficiency requiring renal replacement therapy. Fluorescence in situ hybridization indicated deletion of the entire SALL1 gene. Subsequent aCGH showed a 6 Mb deletion in 16q12q13, which included SALL1. Precise analysis of the present two cases will give us some clues to elucidate the pathogenic mechanisms of 16q12 microdeletion syndrome.     

Purine nucleoside phosphorylase deficiency associated with a dysplastic marrow morphology

Purine nucleoside phosphorylase (PNP) deficiency is an autosomal recessive metabolic disorder characterized by severe combined immunodeficiency and by complex neurologic symptomatology including ataxia, developmental delay, and spasticity. Herein we report severe marrow dysplasia in a patient with PNP deficiency. Drug-related marrow dysfunction was unlikely, and marrow virological studies were negative. A preleukemic myelodysplastic syndrome was also unlikely due to normal marrow CD34+ cells, colony growth in clonogenic assay of marrow mononuclear cells, apoptosis rate, and Fas expression on marrow nucleated cells, as well as morphologic improvement of the marrow dysplasia after normal red blood cell transfusion. The patient's marrow stroma showed hypersensitivity to irradiation and undetectable PNP enzyme activity similar to peripheral lymphocytes. This is the first report of PNP deficiency associated with increased lymphocyte and marrow stromal sensitivity to irradiation. We conclude that marrows from patients with PNP deficiency might have hypersensitivity to irradiation and can develop dysplastic morphology, caused either directly or indirectly by the inherited enzymatic defect.     

Frank -Ter Haar Syndrome in a Newborn

Frank-Ter Haar syndrome is an unusual type of skeletal dysplasia with megalocornea and developmental delay. It is usually transmitted as autosomal recessive disorder. Only a few cases have been reported in the literature and none from India. The authors report a case with other unusual features and a short review of the condition.     

GLUT-1 deficiency syndrome or De Vivo disease: a case report]

GLUT-1 protein is the principal glucose transporter across the blood-brain barrier. GLUT-1 deficiency results in a syndrome of infantile seizures refractory to anticonvulsive drugs, developmental delay, acquired microcephaly and neurologic manifestations including spasticity, hypotonia, and ataxia. A low cerebrospinal fluid glucose concentration in the absence of hypoglycaemia is pathognomonic of glucose transporter deficiency syndrome. Ketogenic diet is an effective treatment of epileptic manifestations but it has less effect on the cognitive symptoms. We report on a child who presented with paroxistical events often occurring prior to meals, developmental delay, microcephaly and spasticity. CSF and serum glucose levels measured simultaneously showed a CSF/serum glucose ratio of 0.39. Molecular analysis identified a heterozygous novel mutation.     

Severe,atypical form of dyschondrosteosis (report of two cases)

We report a mother and her son with unique mesomelic dysplasia. The mesomelic shortening in the upper extremities presents features of Leri-Weill syndrome (dyschondrosteosis) (OMIM 127300), that of the lower extremities is consistent with Langer mesomelic dysplasia (OMIM 249700). Molecular studies showed a heterozygous short stature homeobox gene ( SHOX)deletion in both patients. A second genetic defect in the other SHOX allele was not found. Conclusion:Our study broadens the phenotypic spectrum associated with short stature homeobox gene functional haploinsufficiency.     

一例13号环状染色体综合征患儿的临床及遗传学分析

患儿,女,5个月,因生长发育迟缓就诊,体格检查发现体格发育落后,特殊面容（小头畸形、眼距宽、耳位偏低、鼻梁扁平、短人中）以及一侧小阴唇缺失。外周血染色体核型为46,XX,r（13）（p11q33）[82]/45,XX,-13[10]/46,XX,r（13;13）（p11q33;p11q33）[8];微阵列比较基因组杂交（aCGH）检测显示13q11q33.2区域和13q33.2q34区域分别有87.5 Mb的重复和8.2 Mb的缺失;荧光原位杂交（FISH）显示13号环状染色体长臂末端缺失。诊断为13号环状染色体综合征。该综合征临床表型多变,主要与染色体区带中遗传物质丢失的数量、部位以及不同核型嵌合比例不同等密切相关。     

Osteosclerotic metaphyseal dysplasia: a skeletal dysplasia that may mimic lead poisoning in a child with hypotonia and seizures

We report the case of a 23-month-old male with hypotonia, developmental delay, and complex seizures. Radiographs revealed profound sclerosis of the metaphyses and epiphyses of the long and short bones in the extremities, with a unique pattern of distribution. Sclerosis also involved the anterior ribs, iliac crests, talus, and calcaneus. The skull and vertebral bodies appeared unaffected. Blood lead levels were normal. We believe that this constellation of clinical and radiographic abnormalities closely resembles osteosclerotic metaphyseal dysplasia (OMD) due to an autosomal recessive defect. Characteristic skeletal findings were instrumental in determining the diagnosis. OMD is a very rare sclerosing bone disorder, first described in 1993. The syndrome is characterized clinically by developmental delay of a progressive nature, hypotonia, elevated alkaline phosphatase, and late-onset spastic paraplegia. We encountered a young child with these neurologic symptoms who displayed sclerotic metaphyseal changes on hand radiographs obtained to determine the bone age. Lead poisoning, a known cause of metaphyseal sclerosis, was initially suspected. Careful analysis of the metaphyseal bone changes helped to distinguish this bone dysplasia from lead poisoning and other causes of metaphyseal sclerosis.