Hallermann-streiff syndrome

Overarching control of autophagy and DNA damage response by CHD6 revealed by modeling a rare human pathology

Members of the chromodomain-helicase-DNA binding (CHD) protein family are chromatin remodelers implicated in human pathologies, with CHD6 being one of its least studied members. We discovered a de novo CHD6 missense mutation in a patient clinically presenting the rare Hallermann-Streiff syndrome (HSS). We used genome editing to generate isogenic iPSC lines and model HSS in relevant cell types. By combining genomics with functional in vivo and in vitro assays, we show that CHD6 binds a cohort of autophagy and stress response genes across cell types. The HSS mutation affects CHD6 protein folding and impairs its ability to recruit co-remodelers in response to DNA damage or autophagy stimulation. This leads to accumulation of DNA damage burden and senescence-like phenotypes. We therefore uncovered a molecular mechanism explaining HSS onset via chromatin control of autophagic flux and genotoxic stress surveillance.

Diagnosis, Early Care, and Treatment of Hallermann-Streiff Syndrome: A Review of the Literature

Hallermann-Streiff syndrome is a rare congenital disorder characterized by a wide spectrum of craniofacial abnormalities. A review of the available literature reveals that only approximately 200 cases of the disease have been reported worldwide. For this article, we performed a literature review as a basis for a proposed scheme for early care and treatment. A comprehensive database search was carried out with the use of Medline (PubMed), ISI Web of Science, and ScienceDirect/Scopus. Of the 551 studies initially found, an evaluation using inclusion and exclusion criteria ultimately resulted in a total of 33 articles. Most of the articles are case reports, and only approximately 20% of these articles include treatment options. We propose an early care and treatment schedule based on the presented symptoms. [Pediatr Ann. 2021;50(5):e227-e231.].

Delleman-Oorthuys syndrome (oculocerebrocutaneous syndrome) in a Nigerian child: a case report

Background:

Delleman–Oorthuys syndrome, also known as oculocerebrocutaneous syndrome, is a rare congenital anomaly with ocular, cerebral and cutaneous manifestations. So far, only 40 cases have been described.

Clinical case:

A 3-year-old female Nigerian child with no identifiable left eyeball, multiple left-sided facial skin defects and delayed developmental milestones but otherwise uneventful medical and family history was evaluated at the Ophthalmology and Paediatric Neurosurgery in Ibadan, Nigeria. Besides the mentioned defects that were present since birth, brain imaging revealed several brain abnormalities including intracranial cysts. Global hyperreflexia and bilateral flexor plantar response were observed upon clinical examination. Left micro-ophthalmia and orbital mass were detected. A histological assessment of the orbital mass revealed it to be rudimentary ocular tissue. The diagnosis of Delleman–Oorthuys syndrome was made based on the clinico-radiological features. The patient underwent a left-sided posterior fossa cystoperitoneal shunt. The left orbital mass was enuclated and the patient is currently awaiting left eyelid reconstruction and an orbital implant and repair of the left alar nasi cleft.

Conclusion:

To our knowledge, this is the first published report of Delleman–Oorthuys syndrome in a female child of West African descent. Given the variable manifestations of Delleman–Oorthuys syndrome, and overlap with other syndromes, the Delleman–Oorthuys syndrome may be underreported. Neuroimaging of patients with cutaneous tags, orbital cysts and micro-ophthalmia could reveal more cases.

Diagnosis and Innovative Multidisciplinary Management of Hallermann-Streiff Syndrome: 20-Year Follow-Up of a Patient

Hallermann-Streiff syndrome (HSS) is a rare congenital disorder that mainly affects head and face development. We described the different patterns of the disease throughout the whole growth period and provided innovative treatment steps. Indeed, early genioplasty and dental implantation before growth completion were performed. These steps allowed to improve facial growth and to provide orthodontic anchorage, respectively. Complementary orthognathic surgery achieved satisfactory occlusion and refined aesthetics. We believe such an approach could be considered as a relevant treatment modality to complete multidisciplinary care in patients with HSS.

A familial study of Hallermann-Streiff-François syndrome

Hallermann–Streiff–François syndrome is a rare sporadic genetic pathology characterized by a phenotype consisting of growth retardation, ocular abnormalities, and a “bird-like head”. We hereby report a case of this syndrome found in three generations of the same family – father, daughter, and grand-daughter – who presented with a short stature and facial dysmorphic features, nystagmus, cataract, and bilateral microphthalmia. The discussion is based on the clinical and genetic aspects, and the challenges in management of this oculo-mandibulo-facial syndrome. The association of congenital cataract, facial dysmorphic features, and microphthalmia, should guide the diagnosis of dysmorphic syndromes such as Hallermann–Streiff–François syndrome.

Connexin: a potential novel target for protecting the central nervous system?

Connexin subunits are proteins that form gap junction channels, and play an important role in communication between adjacent cells. This review article discusses the function of connexins/hemichannels/gap junctions under physiological conditions, and summarizes the findings regarding the role of connexins/hemichannels/gap junctions in the physiological and pathological mechanisms underlying central nervous system diseases such as brain ischemia, traumatic brain and spinal cord injury, epilepsy, brain and spinal cord tumor, migraine, neuroautoimmune disease, Alzheimer's disease, Parkinson's disease, X-linked Charcot-Marie-Tooth disease, Pelizaeus-Merzbacher-like disease, spastic paraplegia and maxillofacial dysplasia. Connexins are considered to be a potential novel target for protecting the central nervous system.