BACKGROUND: Bosma arhinia microphthalmia syndrome (BAMS; MIM603457) is a rare genetic disorder, predominantly autosomal dominant. It is a multi-system developmental disorder characterized by severe hypoplasia of the nose and eyes, and reproductive system defects. BAMS is extremely rare in the world and no cases have been reported in Chinese population so far. Pathogenic variants in the SMCHD1 gene (MIM614982) cause BAMS, while the underlying molecular mechanisms requires further investigation.
METHODS: In this study, a Chinese girl who has suffered from congenital absence of nose and microphthalmia was enrolled and subsequently submitted to a comprehensive clinical and genetic evaluation. Whole-exome sequencing (WES) was employed to identify the genetic entity of thisgirl. A heterozygous pathogenic variant, NM_015295, c.1025G > C; p. (Trp342Ser) of SMCHD1 was identified. By performing very detailed physical and genetic examinations, the patient was diagnosed as BAMS.
CONCLUSIONS: This report is the first description of a variant in SMCHD1 in a Chinese patient affected with BAMS.Our study not only furnished valuable genetic data for counseling of BAMS, but also confirmed the diagnosis of BAMS, which may help the management and prognosis for this patient.

Congenital arhinia-microphthalmos syndrome or BOSMA syndrome is an exceptionally rare clinical syndrome characterized by unilateral or bilateral complete absence of the nasal cavity associated with several craniofacial, ocular, and systemic anomalies. Lacrimal drainage anomalies are secondary to absent nasolacrimal duct and usually present as dilated lacrimal sac or mucoceles. While navigation-guided dacryocystorhinostomies into the contralateral nasal cavity are described for unilateral arhinia, the way forward for the complete absence of the nose and nasal cavity is still unclear. A multidisciplinary team from the specialties of genetics, plastic surgery, ophthalmic plastics and reconstructive surgery, otorhinolaryngology, and endocrinology should get involved very early on for better continuity of care.

Congenital arhinia or nasal absence is a rare condition, with only less than 100 cases published in the literature to date. It is a rare condition that causes respiratory distress during the neonatal period. Although stabilization of the airway is the priority, management is not clearly defined, given the rarity of the malformation. We report a case of arhinia in a female newborn and briefly review the literature.

Congenital bony nasal cavity stenosis is caused by alterations of the normal embryological development of the nasal cavity. Depending on the site of the obstruction, the most important types of stenosis are: choanal atresia and stenosis, congenital nasal pyriform aperture stenosis, congenital midnasal stenosis, arhinia and nasal septum deviation. Although they are uncommon, they could be potentially life-threatening conditions that require early diagnosis and proper treatment. In case of neonatal nasal obstruction, appropriate differential diagnosis with other causes, such as rhinitis and sinonasal masses, are performed by nasal endoscopy and radiological exams. Treatment strategy consisting of medical nasal therapies and endoscopic or open nasal surgery should be tailored according to the types and the degree of the stenosis. When indicated, endoscopic endonasal approach is considered the most effective technique in neonates warranting minimal surgical invasiveness and maximum effect. In order to promote the management of these rare yet clinically relevant neonatal nasal breath disorders, we review the current trends in diagnosis and treatment of congenital bony nasal cavity stenosis.

OBJECTIVE: To discuss the presentation and management of infants with arhinia or congenital absence of the nose.
METHODS: This case report describes an infant with arhinia that was diagnosed prenatally. In addition to a discussion of the case, a review of the literature was completed to define appropriate postnatal work-up and management.
RESULTS: The patient is a term male infant, diagnosed with arhinia on ultrasound and magnetic resonance imaging (MRI) performed at 21-weeks gestational age. Upon birth, the patient was subsequently intubated, followed by tracheostomy due to complete nasal obstruction. Through a genetics evaluation, the patient was found to be heterozygous for the SMCHD1 gene, with hypomethylation at the D4Z4 locus. Plans for reconstruction will be based on future imaging and the development of any nasal patency, however, the patient\'s family plans to utilize a prosthetic nose until the patient is older.
CONCLUSIONS: Arhinia is a rare condition causing respiratory distress in the neonatal period. While stabilization of the airway is the first priority, further management is not clearly defined given the rarity of the malformation. This case discusses stabilization of the airway with a review of treatment and reconstructive options.

The reproductive axis is controlled by a network of gonadotropin-releasing hormone (GnRH) neurons born in the primitive nose that migrate to the hypothalamus alongside axons of the olfactory system. The observation that congenital anosmia (inability to smell) is often associated with GnRH deficiency in humans led to the prevailing view that GnRH neurons depend on olfactory structures to reach the brain, but this hypothesis has not been confirmed.
The objective of this work is to determine the potential for normal reproductive function in the setting of completely absent internal and external olfactory structures.
We conducted comprehensive phenotyping studies in 11 patients with congenital arhinia. These studies were augmented by review of medical records and study questionnaires in another 40 international patients.
All male patients demonstrated clinical and/or biochemical signs of GnRH deficiency, and the 5 men studied in person had no luteinizing hormone (LH) pulses, suggesting absent GnRH activity. The 6 women studied in person also had apulsatile LH profiles, yet 3 had spontaneous breast development and 2 women (studied from afar) had normal breast development and menstrual cycles, suggesting a fully intact reproductive axis. Administration of pulsatile GnRH to 2 GnRH-deficient patients revealed normal pituitary responsiveness but gonadal failure in the male patient.
Patients with arhinia teach us that the GnRH neuron, a key gatekeeper of the reproductive axis, is associated with but may not depend on olfactory structures for normal migration and function, and more broadly, illustrate the power of extreme human phenotypes in answering fundamental questions about human embryology.

A male Mongolian child with a complete congenital absence of both nose and nasal passage had a poor survival prognosis due to respiratory distress. To enable his survival, a new nose capable of conferring respiratory function was constructed. Following reconstructive surgery, an absence of mucoepithelium in the nasal passage can lead to rhinostenosis. To avoid this complication, a custom-made nasal silicone stent was created using three-dimensional (3D) printing technology in conjunction with the patient\'s computed tomography data. The stent was implanted for 2 months to maintain the shape and size of the nasal passage. At 2 months after stent implantation, the mucoepithelium tissue in the passage had successfully regenerated with no immune reaction. Three years after stent removal, respiratory function, nasal passage structure, and external nose shape were maintained without additional medical care. These results indicate the successful nasal reconstruction in an arhinia patient using a customized, 3D-printed nasal stent. Laryngoscope, 129:582-585, 2019.

Report of a female fetus aborted at the 25th week of gestation, with severe microcephalus, trigonocephaly, median cleft lip and palate, arhinia, and anophthalmia. On opening of the skull the cranial cavity seemed to be occupied only by hindbrain structures. The forebrain, including the tentorium cerebelli and the falx were absent. However, in the light microscope membraneous remnants of a collapsed forebrain vesicle were found. They were connected with the mid-brain brain and appeared as glio-mesenchymal membranes with an ependymal out-line at their inner surface. There was no cranioschisis. The formal relationship of this forebrain malformation to abobar dorsal sac holoprosencephaly, and its separation from hydranencephaly are discussed. In view of the gross absence of the telencephalon and the microscopic demonstration of remnants of a prosencephalic vesicle it is suggested to term this \"missing link\" in the classification of human CNS malformations pseudoaprosencephaly.

METHODS: Cases of bilateral anterior nasal atresia, sometimes referred to as arhinia or partial arhinia, are extremely rare in cattle and have only been reported as single events. This report describes the birth of 16 Holstein Friesian calves over a 3-month period, all affected with bilateral atresia of the nares and anterior nasal cavity, with 2 calves having additional severe deviation of the nasomaxillary bones and nasal septum. One affected calf was born with an anatomically normal twin. Parentage testing demonstrated that a single Holstein Friesian bull sired all cases tested.
CONCLUSIONS: This is the first report of multiple cases of bilateral anterior nasal atresia in cattle with evidence that demonstrates a heritable condition.

The aim of this study was to illustrate the surgical techniques and utility of stereotactic or image-guided navigation in the management of lacrimal drainage obstruction in congenital arhinia-microphtalmia syndrome and review the relevant literature. Image-guided combined external and endoscopic dacryocystorhinostomy was performed in a female, aged 16 years with congenital partial arhinia and ipsilateral microphthalmus. The lacrimal sac was bypassed to the contra lateral nasal cavity through a septal window. The surgical procedure was performed using the intra-operative optical image-guided Nav 1 PicoTM ENT navigation system with real-time intra-operative instrument geometry. Different phases of the surgical technique, adjunctive endoscopic procedures, intra-operative anatomical guidance, and utility at crucial phases of surgery were noted. A review of the literature was performed pertinent to arhinia and navigation guided lacrimal surgeries. Lacrimal bypass into the contra lateral nasal cavity even through a malformed septum is possible in partial arhinia syndromes. Detailed preoperative evaluation including 3D imaging studies, navigation guided planning of risk structures with intra-operative distance control and construction of meticulous surgical roadmaps were found to be essential factors in successful outcomes. At six months follow up after surgery, there was a complete and contiguous healed mucosal anastomosis with lacrimal system patent on irrigation and resolution of epiphora. Combined external and endoscopic approach is useful in partial arhinia syndromes. Image guidance is a very useful adjunctive tool that facilitates safe and precise surgery in the management of such complex lacrimal surgeries.