Vascular Ehlers-Danlos syndrome (vEDS) is characterized by arterial, intestinal, and/or uterine fragility; thin, translucent skin; easy bruising; characteristic facial appearance (thin vermilion of the lips, micrognathia, narrow nose, prominent eyes); and an aged appearance to the extremities, particularly the hands. Vascular dissection or rupture, gastrointestinal perforation, or organ rupture are the presenting signs in most adults with vEDS. Arterial rupture may be preceded by aneurysm, arteriovenous fistulae, or dissection but also may occur spontaneously. The majority (60%) of individuals with vEDS who are diagnosed before age 18 years are identified because of a positive family history. Neonates may present with clubfoot, hip dislocation, limb deficiency, and/or amniotic bands. Approximately half of children tested for vEDS in the absence of a positive family history present with a major complication at an average age of 11 years. Four minor diagnostic features – distal joint hypermobility, easy bruising, thin skin, and clubfeet – are most often present in those children ascertained without a major complication.

ESCO2 spectrum disorder is characterized by mild-to-severe prenatal growth restriction, limb malformations (which can include bilateral symmetric tetraphocomelia or hypomelia caused by mesomelic shortening), hand anomalies (including oligodactyly, thumb aplasia or hypoplasia, and syndactyly), elbow and knee flexion contractures (involving elbows, wrists, knees, ankles, and feet [talipes equinovarus]), and craniofacial abnormalities (which can include bilateral cleft lip and/or cleft palate, micrognathia, widely spaced eyes, exophthalmos, downslanted palpebral fissures, malar flattening, and underdeveloped ala nasi), ear malformation, and corneal opacities. Intellectual disability (ranging from mild to severe) is common. Early mortality is common among severely affected pregnancies and newborns; mildly affected individuals may survive to adulthood.

Wiedemann-Rautenstrauch syndrome (WDRTS) is a rare autosomal recessive neonatal progeroid disorder characterized by intrauterine growth retardation, failure to thrive, short stature, a progeroid appearance, hypotonia, and variable mental impairment (summary by Toriello, 1990). Average survival in WDRTS is 7 months, although survival into the third decade of life has been reported (Akawi et al., 2013).

Oculoauricular syndrome (OCACS) is characterized by complex ocular anomalies, including congenital cataract, anterior segment dysgenesis, iris coloboma, and early-onset retinal dystrophy, and dysplastic ears with abnormal external ear cartilage (summary by Gillespie et al., 2015).

Ehlers-Danlos syndrome spondylodysplastic type 1 (EDSSPD1) is characterized by short stature, developmental anomalies of the forearm bones and elbow, and bowing of extremities, in addition to the classic stigmata of Ehlers-Danlos syndrome, including joint laxity, skin hyperextensibility, and poor wound healing. Significant developmental delay is not a consistent feature (Guo et al., 2013). Genetic Heterogeneity of Ehlers-Danlos Syndrome, Spondylodysplastic Type See EDSSPD2 (615349), caused by mutation in the B3GALT6 gene (615291), and EDSSPD3 (612350), caused by mutation in the SLC39A13 gene (608735).

Menke-Hennekam syndrome-1 (MKHK1) is a congenital disorder characterized by variable impairment of intellectual development and facial dysmorphisms. Feeding difficulties, autistic behavior, recurrent upper airway infections, hearing impairment, short stature, and microcephaly are also frequently seen. Although mutations in the same gene cause Rubinstein-Taybi syndrome-1 (RSTS1; 180849), patients with MKHK1 do not resemble the striking phenotype of RSTS1. Genetic Heterogeneity of Menke-Hennekam Syndrome Menke-Hennekam syndrome-2 (MKHK2; 618333) is caused by heterozygous mutation in exons 30 or 31 of the EP300 gene (602700). Mutation elsewhere in that gene results in RSTS2 (613684).

Menke-Hennekam syndrome-2 (MKHK2) is a congenital disorder characterized by variable impairment of intellectual development and facial dysmorphisms. Feeding difficulties, autistic behavior, recurrent upper airway infections, and hearing impairment are also frequently seen. Although mutations in the same gene cause Rubinstein-Taybi syndrome-2 (RSTS2; 613684), patients with MKHK1 do not resemble the striking phenotype of RSTS2. For a discussion of genetic heterogeneity of Menke-Hennekam syndrome, see MKHK1 (618332).

SIMHA syndrome is characterized by short stature, impaired intellectual development, microcephaly, hypotonia, and ocular anomalies. Inter- and intrafamilial phenotypic variability has been observed (Kambouris et al., 2014; Zahra et al., 2020).

Autosomal dominant intellectual developmental disorder-68 (MRD68) is characterized by developmental delay/intellectual disability, microcephaly, poor growth, feeding difficulties, and dysmorphic features. Some patients may have autism spectrum disorder or attention deficit-hyperactivity disorder (ADHD) (Cif et al., 2020).