CHD7 disorder encompasses the entire phenotypic spectrum of heterozygous CHD7 pathogenic variants that includes CHARGE syndrome as well as subsets of features that comprise the CHARGE syndrome phenotype. The mnemonic CHARGE syndrome, introduced in the premolecular era, stands for coloboma, heart defect, choanal atresia, retarded growth and development, genital hypoplasia, ear anomalies (including deafness). Following the identification of the genetic cause of CHD7 disorder, the phenotypic spectrum expanded to include cranial nerve anomalies, vestibular defects, cleft lip and/or palate, hypothyroidism, tracheoesophageal anomalies, brain anomalies, seizures, and renal anomalies. Life expectancy highly depends on the severity of manifestations; mortality can be high in the first few years when severe birth defects (particularly complex heart defects) are present and often complicated by airway and feeding issues. In childhood, adolescence, and adulthood, decreased life expectancy is likely related to a combination of residual heart defects, infections, aspiration or choking, respiratory issues including obstructive and central apnea, and possibly seizures. Despite these complications, the life expectancy for many individuals can be normal.

Syndrome that has characteristics of dysmorphic features and intellectual deficit. It has been described in seven patients within one family. 17q11.2 microduplication encompasses the NF1 region. The underlying mechanism may be non-allelic homologous recombination. The study of pedigree suggests that this microduplication segregates within the family for at least two generations. Two patients displayed a normal clinical presentation, suggesting an autosomal dominant pattern of inheritance with incomplete penetrance.

Autosomal recessive osteopetrosis-8 (OPTB8) is characterized by the 'classical' features of osteopetrosis, macrocephaly, hepatosplenomegaly, and visual impairment, with varying severity (summary by Megarbane et al., 2013). For a general phenotypic description and a discussion of genetic heterogeneity of autosomal recessive osteopetrosis, see OPTB1 (259700).

X-linked deafness-7 (DFNX7) is a congenital form of bilateral mixed or conductive hearing loss, which may be progressive. It is not associated with vestibular symptoms (Xing et al., 2017).

Oculogastrointestinal neurodevelopmental syndrome (OGIN) is characterized by microphthalmia and/or coloboma in association with other congenital anomalies, including imperforate anus, horseshoe kidney, and structural cardiac defects. Hearing loss and severe developmental delay are also observed in most patients (Zha et al., 2020; Mor-Shaked et al., 2021).