MedGen

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. [from GeneReviews]

Holt-Oram syndrome (HOS) is characterized by upper-limb defects, congenital heart malformation, and cardiac conduction disease. Upper-limb malformations may be unilateral, bilateral/symmetric, or bilateral/asymmetric and can range from triphalangeal or absent thumb(s) to phocomelia. Other upper-limb malformations can include unequal arm length caused by aplasia or hypoplasia of the radius, fusion or anomalous development of the carpal and thenar bones, abnormal forearm pronation and supination, abnormal opposition of the thumb, sloping shoulders, and restriction of shoulder joint movement. An abnormal carpal bone is present in all affected individuals and may be the only evidence of disease. A congenital heart malformation is present in 75% of individuals with HOS and most commonly involves the septum. Atrial septal defect and ventricular septal defect can vary in number, size, and location. Complex congenital heart malformations can also occur in individuals with HOS. Individuals with HOS with or without a congenital heart malformation are at risk for cardiac conduction disease. While individuals may present at birth with sinus bradycardia and first-degree atrioventricular (AV) block, AV block can progress unpredictably to a higher grade including complete heart block with and without atrial fibrillation. [from GeneReviews]

Gollop-Wolfgang complex (GWC) is a rare congenital limb anomaly characterized by bifurcation of the femur with ipsilateral tibial aplasia and split hand and monodactyly of the feet, resulting in severe and complex limb deformities. Variable expressivity and incomplete penetrance have been reported (Odrzywolski et al., 2024). [from OMIM]

A rare genetic congenital limb malformation disorder with characteristics of the presence of a single digit on all four extremities. The malformation is typically isolated however, aplastic and hypoplastic defects in the remaining skeletal parts of hands and feet have been reported. There have been no further descriptions in the literature since 1992. [from SNOMEDCT_US]

A rare syndrome with characteristics of split-hand and split-foot deformity and ocular abnormalities mainly a congenital nystagmus. Ten cases from four families have been reported in the literature. In some cases the hands are monodactylous. The affected patients have normal mental development. The condition seems to be autosomal dominant with a relatively high proportion of gonadal mosaicism. [from SNOMEDCT_US]