Tarsal-carpal coalition syndrome is a rare, inherited bone disorder that affects primarily the hands and feet. Several individual bones make up each wrist (carpal bones) and ankle (tarsal bones). In tarsal-carpal coalition syndrome, the carpal bones fuse together, as do the tarsal bones, which causes stiffness and immobility of the hands and feet. Symptoms of the condition can become apparent in infancy, and they worsen with age. The severity of the symptoms can vary, even among members of the same family.\n\nIn this condition, fusion at the joints between the bones that make up each finger and toe (symphalangism) can also occur. Consequently, the fingers and toes become stiff and difficult to bend. Stiffness of the pinky fingers and toes (fifth digits) is usually noticeable first. The joints at the base of the pinky fingers and toes fuse first, and slowly, the other joints along the length of these digits may also be affected. Progressively, the bones in the fourth, third, and second digits (the ring finger, middle finger, and forefinger, and the corresponding toes) become fused. The thumb and big toe are usually not involved. Affected individuals have increasing trouble forming a fist, and walking often becomes painful and difficult. Occasionally, there is also fusion of bones in the upper and lower arm at the elbow joint (humeroradial fusion). Less common features of tarsal-carpal coalition syndrome include short stature or the development of hearing loss.

A rare genetic multiple congenital anomalies/dysmorphic syndrome with characteristics of dysmorphic facial features including high forehead, elongated and flattened midface, arched and sparse eyebrows, short palpebral fissures, telecanthus, long nose with hypoplastic nostrils, long philtrum, high and narrow palate and microstomia with downturned corners. Ears are characteristically malformed, large, low-set and posteriorly rotated and nasal speech is associated.

The overlapping phenotypes of neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD) represent the milder manifestations of the Zellweger syndrome spectrum (ZSS) of peroxisome biogenesis disorders. The clinical course of patients with the NALD and IRD presentation is variable and may include developmental delay, hypotonia, liver dysfunction, sensorineural hearing loss, retinal dystrophy, and visual impairment. Children with the NALD presentation may reach their teens, and those with the IRD presentation may reach adulthood (summary by Waterham and Ebberink, 2012). For a complete phenotypic description and a discussion of genetic heterogeneity of PBD(NALD/IRD), see 601539. Individuals with mutations in the PEX13 gene have cells of complementation group 13 (CG13, equivalent to CGH). For information on the history of PBD complementation groups, see 214100.

Some ectodermal dysplasias are here classified as congenital disorders characterized by abnormal development in 2 or more ectodermal structures (hair, nails, teeth, and sweat glands) without other systemic findings. Ectodermal dysplasia-14 of the hair/tooth type (ECTD14) is primarily characterized by scalp hypotrichosis and hypodontia. Some patients have decreased sweating, and some show subtle facial dysmorphism (Peled et al., 2016). Rabie et al. (2022) tabulated the features of 24 patients with TSPEAR-associated ectodermal dysplasia, and found that of the various ectodermal derivatives, teeth were the most affected (82.6%), followed by hair (78.3%), nails (43.5%), and sweat glands (39.1%). The authors also noted that TSPEAR-associated dysmorphic facial features varied according to ethnic origin.