# Treatment of Orthopathic Surgical Class III Patient with Coffin-Siris Syndrome: A Case Report
## 1 Introduction  
Coffin-Siris syndrome (CSS) is a multisystem congenital anomaly caused by mutations in genes of the BRG1- and BRM-associated factor complexes, including _ARID1A_, _ARID1B_, _ARID2_, _DPF2_, _SMARCA4_, _SMARCB1_, _SMARCC2_, _SMARCE1_, _SOX11_, and _SOX4_. [1; 2; 3]. Recent discoveries have underlined the importance of the BAF complex in human neuronal development and cancer occurrence (three especially well-studied complex assemblies are esBAF, npBAF, and nBAF), whereby mutations in their subunit genes and related genes are implicated in several nonverbal ID (intellectual disability) syndromes such as CSS, autism spectrum disorder, and schizophrenia, as well as in cancers/cancer predisposing syndromes [4; 5]. In 1970, [PERSON] and [PERSON] were the first ones to describe three girls with similar phenotypic traits and manifestations, including severe intellectual disability and developmental delay, growth retardation, lax joints, and absent or hypoplastic fifth distal phalanges andails [6]. Other findings included a coarse facial appearance, feeding difficulties, frequent infections, and cardiac/neurological/gastrointestinal/genitourinary anomalies [7]. The typical features of Coffin-Siris syndrome result from the involvement of ectodermal tissues. Abnormal or delayed dentition is also reported frequently [2; 8]. Fewer than 200 individuals with molecularly confirmed Coffin-Siris syndrome have been reported, indicating and underlining that the diagnosis is rare and difficult. It has to be considered that these numbers are likely underestimated, since not all individuals may have sought medical attention. In addition, the identification of a pathogenic variant in \(ARID1B\) in some members of a large cohort with intellectual disability suggests that the prevalence of pathogenic variants in genes associated with CSS (and of subtle phenotypic features of CSS) may be higher than is currently appreciated among those with intellectual disability [2; 9]. The penetrance for Coffin-Siris syndrome appears to be complete. More females than males with CSS were reported in the literature prior to 2001 [6]. In cases of molecularly confirmed CSS, the male-female ratios are similar [10; 11]. No evidence exists for X-linked dominant, sex-limited, or mitochondrial inheritance [2]. Individuals with Coffin-Siris syndrome have a distinct appearance, with overall typically coarse facial features. In early childhood, individuals with CSS usually have a round face with thick and arched eyebrows, a short nose with a bulbous tip, and anteverted nostrils, a long philtrum, a small mouth, and micro-retrognathia. Adults tend to have a broad nasal bridge without anteverted nostrils, a broad philtrum, a large tongue, and prognathism [12]. Common findings include a wide mouth and thick lips. The palate is generally highly arched and a cleft palate is occasionally present. Another common feature is abnormal ears, either in shape or position. Less frequent findings are ptosis, a short philtrum, and macroglossia [13]. Because of micrognathia, macroglossia, hypotonia, and lax joints, dental and orthodontic management can be challenging in these children, as well as communication because of their IDs. Dentists should be aware that proper motivation and psychological support for the patients and their families are essential to achieve a functional and aesthetical dentition and occlusion [7; 14]. The most common and significant oral health problems in these patients are gingival and periodontal diseases, which usually lead to the loss of permanent anterior teeth in their young adulthood. Some factors can contribute to such evolution, including malocclusion, bruism, conical-shaped tooth roots, and an abnormal host response because of a compromised immune system [14]. This article describes the treatment of a patient affected by CSS through orthognathic surgery and pre- and post-surgical orthodontic treatment.