Filippi syndrome is characterized by short stature, microcephaly, syndactyly, intellectual disability, and facial dysmorphism consisting of bulging forehead, broad and prominent nasal bridge, and diminished alar flare. Common features include cryptorchidism, speech impairment, and clinodactyly of the fifth finger, Some patients exhibit visual disturbances, polydactyly, seizures, and/or ectodermal abnormalities, such as nail hypoplasia, long eyelashes, hirsutism, and microdontia (summary by Hussain et al., 2014).

Congenital hypotrichosis with juvenile macular dystrophy (HJMD) is an autosomal recessive disorder characterized by hair loss followed by progressive macular degeneration and early blindness. Scalp hair is lost during the first months of life, with onset of retinal degeneration and vision loss a few years to 2 decades later (summary by Sprecher et al., 2001 and Indelman et al., 2002).

A very rare hereditary skin disease with manifestation of irregularly distributed epidermal hyperkeratosis of the palms and soles. Reported in 35 families worldwide to date. The lesions usually start to develop in early adolescence but can also present later in life. Mutations in the AAGAB gene (15q22.33-q23) have recently been identified as one of the causes. Mutations in the COL14A1 gene (8q23) have also been identified as causal in some cases in Asia that seem to have a similar phenotype

Weill-Marchesani syndrome (WMS) is a connective tissue disorder characterized by abnormalities of the lens of the eye, short stature, brachydactyly, joint stiffness, and cardiovascular defects. The ocular problems, typically recognized in childhood, include microspherophakia (small spherical lens), myopia secondary to the abnormal shape of the lens, ectopia lentis (abnormal position of the lens), and glaucoma, which can lead to blindness. Height of adult males is 142-169 cm; height of adult females is 130-157 cm. Autosomal recessive WMS cannot be distinguished from autosomal dominant WMS by clinical findings alone.

Distal monosomy 6p is responsible for a distinct chromosome deletion syndrome with a recognizable clinical picture including intellectual deficit, ocular abnormalities, hearing loss, and facial dysmorphism.

Any hypotrichosis in which the cause of the disease is a mutation in the KRT71 gene.

Weill-Marchesani syndrome (WMS) is a connective tissue disorder characterized by abnormalities of the lens of the eye, short stature, brachydactyly, joint stiffness, and cardiovascular defects. The ocular problems, typically recognized in childhood, include microspherophakia (small spherical lens), myopia secondary to the abnormal shape of the lens, ectopia lentis (abnormal position of the lens), and glaucoma, which can lead to blindness. Height of adult males is 142-169 cm; height of adult females is 130-157 cm. Autosomal recessive WMS cannot be distinguished from autosomal dominant WMS by clinical findings alone.

Schimmelpenning-Feuerstein-Mims syndrome, also known as linear sebaceous nevus syndrome, is characterized by sebaceous nevi, often on the face, associated with variable ipsilateral abnormalities of the central nervous system, ocular anomalies, and skeletal defects (summary by Happle, 1991 and Ernst et al., 2007). The linear sebaceous nevi follow the lines of Blaschko (Hornstein and Knickenberg, 1974; Bouwes Bavinck and van de Kamp, 1985). All cases are sporadic. The syndrome is believed to be caused by an autosomal dominant lethal mutation that survives by somatic mosaicism (Gorlin et al., 2001).

EKVP6 is characterized by erythematous hyperkeratotic plaques that develop within the first year of life, beginning on distal extremities and progressing to involve the face, wrists, and ankles, with sparing of volar surfaces. Intrafamilial variation in severity has been observed, and most affected individuals experience slowly progressive spontaneous remission after puberty (Wang et al., 2019). For a general phenotypic description and discussion of genetic heterogeneity of EKVP, see EKVP1 (133200).

Den Hoed-de Boer-Voisin syndrome (DHDBV) is characterized by global developmental delay with moderately to severely impaired intellectual development, poor or absent speech, and delayed motor skills. Although the severity of the disorder varies, many patients are nonverbal and have hypotonia with inability to sit or walk. Early-onset epilepsy is common and may be refractory to treatment, leading to epileptic encephalopathy and further interruption of developmental progress. Most patients have feeding difficulties with poor overall growth and dysmorphic facial features, as well as significant dental anomalies resembling amelogenesis imperfecta. The phenotype is reminiscent of Kohlschutter-Tonz syndrome (KTZS; 226750). More variable features of DHDBV include visual defects, behavioral abnormalities, and nonspecific involvement of other organ systems (summary by den Hoed et al., 2021).