Long-term follow-up of four patients with Langer-Giedion syndrome: clinical course and complications

Trichorhinophalangeal syndrome type II associated with aplasia cutis congenita in a neonate

Aplasia cutis congenita (ACC) was diagnosed in a newborn with dysmorphic facial features, oligodactyly of the bilateral feet, and hip instability. The neonate's clinical abnormalities in addition to genetic testing confirmed a diagnosis of trichorhinophalangeal syndrome (TRPS) type II. The possibility of concurrent Adams-Oliver syndrome (AOS) is raised.

Minimal Critical Region and Genes for a Typical Presentation of Langer-Giedion Syndrome

Langer-Giedion syndrome (LGS) is caused by a contiguous deletion at 8q23q24, characterized by exostoses, facial, ectodermal, and skeletal anomalies, and, occasionally, intellectual disability. LGS patients have been diagnosed clinically or by routine cytogenetic techniques, hampering the definition of an accurate genotype-phenotype correlation for the syndrome. We report two unrelated patients with 8q23q24 deletions, characterized by cytogenomic techniques, with one of them, to our knowledge, carrying the smallest deletion reported in classic LGS cases. We assessed the pathogenicity of the deletion of genes within the 8q23q24 region and reviewed other molecularly confirmed cases from the literature. Our findings suggest a 3.2-Mb critical region for a typical presentation of the syndrome, emphasizing the contribution of the TRPS1, RAD21, and EXT1 genes' haploinsufficiency, and facial dysmorphisms as well as bone anomalies as the most frequent features among patients with LGS. We also suggest a possible role for the CSMD3 gene, whose deletion seems to contribute to central nervous system anomalies. Since studies performing such correlation for LGS patients are limited, our data contribute to improving the ge-notype-phenotype characterization for LGS patients.

Long-read DNA sequencing fully characterized chromothripsis in a patient with Langer-Giedion syndrome and Cornelia de Lange syndrome-4

Chromothripsis is a type of chaotic complex genomic rearrangement caused by a single event of chromosomal shattering and repair processes. Chromothripsis is known to cause rare congenital diseases when it occurs in germline cells, however, current genome analysis technologies have difficulty in detecting and deciphering chromothripsis. It is possible that this type of complex rearrangement may be overlooked in rare-disease patients whose genetic diagnosis is unsolved. We applied long read nanopore sequencing and our recently developed analysis pipeline dnarrange to a patient who has a reciprocal chromosomal translocation t(8;18)(q22;q21) as a result of chromothripsis between the two chromosomes, and fully characterize the complex rearrangements at the translocation site. The patient genome was evidently shattered into 19 fragments, and rejoined into derivative chromosomes in a random order and orientation. The reconstructed patient genome indicates loss of five genomic regions, which all overlap with microarray-detected copy number losses. We found that two disease-related genes RAD21 and EXT1 were lost by chromothripsis. These two genes could fully explain the disease phenotype with facial dysmorphisms and bone abnormality, which is likely a contiguous gene syndrome, Cornelia de Lange syndrome type IV (CdLs-4) and atypical Langer-Giedion syndrome (LGS), also known as trichorhinophalangeal syndrome type II (TRPSII). This provides evidence that our approach based on long read sequencing can fully characterize chromothripsis in a patient's genome, which is important for understanding the phenotype of disease caused by complex genomic rearrangement.

Non-ossifying fibroma with a pathologic fracture in a 12-year-old girl with tricho-rhino-phalangeal syndrome: a case report

Background

Tricho-rhino-phalangeal syndrome (TRPS) is a rare autosomal dominant genetic disorder characterized by distinctive craniofacial and skeletal abnormalities, while non-ossifying fibroma (NOF) is a common benign bone tumour in children and adolescents. To date, no case of TRPS coexisting with NOF has been reported. This report presents a 12-year-old girl who had the characteristic features of tricho-rhino-phalangeal syndrome and non-ossifying fibroma with a fibula fracture.

Case presentation

A 12-year-old girl was admitted to the Department of Endocrinology and Diabetes for evaluation of brachydactyly and a right fibula fracture. Clinical examination revealed sparse scalp hair, a characteristic bulbous pear-shaped nose, and brachydactyly with significant shortening of the fourth metatarsal. Neither intellectual disability nor multiple exostoses were observed. Radiography of both hands showed brachydactyly and cone-shaped epiphyses of the middle phalanges of the digits of both hands with deviation of the phalangeal axis. Genetic analysis of TRPS1 identified a heterozygous germline sequence variant (p.Ala932Thr) in exon 6 in the girl and her father. Approximately 1 month before being admitted to our department, the girl experienced a minor fall and suffered a fracture of the proximal fibula in the right lower limb. The pathological cytological diagnosis of the osteolytic lesion was NOF. Ten months following the surgery, the lesion on the proximal fibula of the girl disappeared.

Conclusions

In conclusion, the present study is the first to report a rare case of NOF with a pathologic fracture in the fibula of a girl with TRPS. The identification of a missense mutation, (p.Ala932Thr), in exon 6 of TRPS1 in this kindred further suggested that the patient had type I TRPS and indicated that mutations in this exon may be correlated with more pronounced features of the syndrome. Radiological techniques and genetic analysis played key roles in the definitive diagnosis.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0732-4) contains supplementary material, which is available to authorized users.

Hydrometrocolpos etiology and management: past beckons the present

Hydrometrocolpos is a rare condition in which the uterus and the vagina are grossly distended with a retained fluid other than pus or blood. It may present during the neonatal period or later at puberty. Most cases reported earlier were stillbirths and were diagnosed only on autopsy. Antenatal diagnosis is now possible with the advent of ultrasound. An early diagnosis and speedy management is the key to survival. Many previous case reports have focused on the varied clinical presentations, multiple causes, associated syndromes and/or the radiological diagnosis of this condition. However, management options for different types of hydrometrocolpos have not yet been concisely discussed. We have reviewed the literature and tried to summarize the management options applicable to most case scenarios of hydrometrocolpos.

Annular pancreas in Trichorhinophalangeal syndrome type II with 8q23.3-q24.12 interstitial deletion

Background

Trichorhinophalangeal syndrome type II (TRPS II, OMIM # 150230) is a rare autosomal dominant genetic disorder characterized by craniofacial and skeletal abnormalities. Loss of functional copies of the TRPS1 gene at 8q23.3 and the EXT1 gene at 8q24.11 are considered to be responsible for the syndrome.

Case Presentation

Herewith, we report an 8-year-old girl with sparse scalp hair, bulbous nose, thin upper lip, broad eyebrows, phalangeal abnormalities of both hands/toes, multiple exostoses, mild intellectual impairment and severe malnutrition. In addition, the patient also had annular pancreas, a rare co-existing feature in patients with TRPS II.

Conclusions

A contiguous 5.47 Mb deletion involving 8q23.3-q24.12 was detected by array comparative genomic hybridization (aCGH), leading to haploinsufficiency of 10 protein coding genes, 1 long non-coding RNA and 1 microRNA. Quantitative PCR (qPCR) examination confirmed half-reduced DNA copy of the patient and normal expression of both parents, indicating a de novo origin of the deletion and complete penetrance of the mutation.

An interstitial deletion at 8q23.1-q24.12 associated with Langer-Giedion syndrome/ Trichorhinophalangeal syndrome (TRPS) type II and Cornelia de Lange syndrome 4

Background

There are three distinct subtypes of Trichorhinophalangeal syndrome (TRPS); TRPS type I, TRPS type II and TRPS type III. Features common to all three subtypes include sparse, slowly growing scalp hair, laterally sparse eyebrows, a bulbous tip of the nose (pear-shaped), and protruding ears. Langer–Giedion syndrome (LGS) or TRPS type II is a contiguous gene syndrome on 8q24.1, involving loss of functional copies of the TRPS1 and EXT1 genes. We report a male patient that was referred to the Department of Medical Genetics due to hypotonia and dysmorphic facial features.

Results

Cytogenetic and array- Comparative Genomic Hybridization (aCGH) analysis revealed that the patient was a carrier of an interstitial deletion at 8q23.1-q24.12 of 12,5 Mb. Parental karyotype indicated that the father carried an apparently balanced insertion: 46, ΧΥ, der(10)ins(10;8)(q22;q23q24).

Conclusions

This is the first report of an apparently balanced insertion including chromosomes 8 and 10 contributing to the etiology of LGS/ TRPS type II. Τimely diagnosis of parental balanced chromosomal rearrangements can reduce the risk of subsequent miscarriages as well as abnormal offspring.

Traumatic bone cyst of the mandible in Langer-Giedion syndrome: a case report

Introduction

Langer-Giedion syndrome (trichorhinophalangeal syndrome type II) is an extremely rare disorder characterized by dysmorphic facial features, multiple exostoses, mental retardation and digit deformities. We report the first case of any maxillofacial pathology in such a syndromic patient.

Case presentation

A 22-year-old Indian woman with mild intellectual disability presented with malaligned teeth. Routine radiographic screening demonstrated a large multilocular lesion in her right mandible. She had peculiar features such as short stature, short limbs, brachydactyly, and dysmorphic facial characters, which prompted us to evaluate her further. After findings of multiple bony exostoses she was diagnosed with Langer-Giedion syndrome. On surgical exploration of her right mandibular lesion an empty cavity was found suggestive of traumatic bone cyst. The lesion healed completely after 1 year without loss of vitality of any teeth.

Conclusions

Although diagnosis and management of any maxillofacial pathology can be challenging in syndromic patients, our report suggests a possible correlation between traumatic bone cyst and Langer-Giedion syndrome. Clinicians should routinely screen these patients for any undetected maxillofacial pathology. In future cases of this syndrome, one should consider the possibility of traumatic bone cyst which may not require aggressive surgical management.

Human molecular cytogenetics: From cells to nucleotides

The field of cytogenetics has focused on studying the number, structure, function and origin of chromosomal abnormalities and the evolution of chromosomes. The development of fluorescent molecules that either directly or via an intermediate molecule bind to DNA has led to the development of fluorescent in situ hybridization (FISH), a technology linking cytogenetics to molecular genetics. This technique has a wide range of applications that increased the dimension of chromosome analysis. The field of cytogenetics is particularly important for medical diagnostics and research as well as for gene ordering and mapping. Furthermore, the increased application of molecular biology techniques, such as array-based technologies, has led to improved resolution, extending the recognized range of microdeletion/microduplication syndromes and genomic disorders. In adopting these newly expanded methods, cytogeneticists have used a range of technologies to study the association between visible chromosome rearrangements and defects at the single nucleotide level. Overall, molecular cytogenetic techniques offer a remarkable number of potential applications, ranging from physical mapping to clinical and evolutionary studies, making a powerful and informative complement to other molecular and genomic approaches. This manuscript does not present a detailed history of the development of molecular cytogenetics; however, references to historical reviews and experiments have been provided whenever possible. Herein, the basic principles of molecular cytogenetics, the technologies used to identify chromosomal rearrangements and copy number changes, and the applications for cytogenetics in biomedical diagnosis and research are presented and discussed.