MedGen

Lymphedema-distichiasis syndrome (referred to as LDS in this GeneReview) is characterized by lower-limb lymphedema, and distichiasis (aberrant eyelashes ranging from a full set of extra eyelashes to a single hair). Lymphedema typically appears in late childhood or puberty, is confined to the lower limbs with or without involvement of the external genitalia, and is often asymmetric; severity varies within families. Males develop edema at an earlier age and have more problems with cellulitis than females. Distichiasis, which may be present at birth, is observed in 94% of affected individuals. About 75% of affected individuals have ocular findings including corneal irritation, recurrent conjunctivitis, and photophobia; other common findings include varicose veins and ptosis. [from GeneReviews]

Myopathy, lactic acidosis, and sideroblastic anemia (MLASA) is a rare autosomal recessive oxidative phosphorylation disorder specific to skeletal muscle and bone marrow (Bykhovskaya et al., 2004). Genetic Heterogeneity of Myopathy, Lactic Acidosis, and Sideroblastic Anemia MLASA2 (613561) is caused by mutation in the YARS2 gene (610957) on chromosome 12p11. MLASA3 (500011) is caused by heteroplasmic mutation in the mitochondrially-encoded MTATP6 gene (516060). [from OMIM]

The blepharocheilodontic syndrome is a rare autosomal dominant disorder characterized by lower eyelid ectropion, upper eyelid distichiasis, euryblepharon, bilateral cleft lip and palate, and conical teeth. An additional rare manifestation is imperforate anus (summary by Weaver et al., 2010). [from OMIM]

The focal dermal dysplasias (FFDDs) are a group of related developmental defects characterized by bitemporal or preauricular skin lesions resembling aplasia cutis congenita. FFFD3 is an autosomal recessive disorder characterized by bitemporal skin lesions with variable facial findings, including thin and puckered periorbital skin, distichiasis and/or absent eyelashes, upslanting palpebral fissures, a flat nasal bridge with a broad nasal tip, large lips, and redundant facial skin (summary by Slavotinek et al., 2013). FFDD2 (614973) is characterized by the same facial features as FFDD3, but the inheritance is autosomal dominant. For a classification and a discussion of genetic heterogeneity of FFDD, see FFDD1 (136500). [from OMIM]

Double rows of eyelashes. [from HPO]

Blepharocheilodontic (BCD) syndrome is a disorder that is present at birth. It mainly affects the eyelids (blepharo-), upper lip (-cheilo-), and teeth (-dontic).

People with BCD syndrome have lower eyelids that turn out so that the inner surface is exposed (ectropion). The outside of the lower lid may sag away from the eye (euryblepharon), and the eyelids may not be able to close completely (lagophthalmia). There can be extra eyelashes (distichiasis) on the upper eyelids, ranging from a few extra eyelashes to a full extra set. These eyelashes do not grow along the edge of the eyelid with the normal lashes, but out of its inner lining. When the abnormal eyelashes touch the eyeball, they can cause damage to the clear covering of the eye (cornea). Affected individuals may also have widely spaced eyes (hypertelorism), a flat face, and a high forehead.

Other features of BCD syndrome usually include openings on both sides of the upper lip (bilateral cleft lip) and an opening in the roof of the mouth (cleft palate). Affected individuals may have fewer teeth than normal (oligodontia) and their teeth are often smaller than usual and cone-shaped. The dental abnormalities affect both primary teeth (sometimes called "baby teeth") and secondary (permanent) teeth. Other frequent features include sparse, fine hair and abnormal nails.

Occasionally people with BCD syndrome have additional features, including an obstruction of the anal opening (imperforate anus); malformation or absence of the butterfly-shaped gland in the lower neck called the thyroid, resulting in lack of thyroid gland function; or fused fingers or toes (syndactyly). Very rarely, affected individuals have incompletely formed arms or legs (limb reduction defects) or a spinal cord abnormality known as spina bifida. [from MedlinePlus Genetics]

The focal dermal dysplasias (FFDDs) are a group of related developmental defects characterized by bitemporal or preauricular skin lesions resembling aplasia cutis congenita. Cervantes-Barragan et al. (2011) proposed a classification of FFDD in which there are 4 subtypes. FFDD1 (Brauer syndrome) is characterized by temporal skin depressions that resemble 'forceps marks.' Other facial anomalies, comprising sparse lateral eyebrows, distichiasis, and a flattened nasal tip, are usually mild. Inheritance is autosomal dominant. FFFD2 (Brauer-Setleis syndrome; 614973) is characterized by bitemporal skin lesions with variable facial findings, including thin and puckered periorbital skin, distichiasis and/or absent eyelashes, upslanting palpebral fissures, a flat nasal bridge with a broad nasal tip, large lips, and redundant facial skin. Inheritance is autosomal dominant. FFDD3 (Setleis syndrome; 227260) is characterized by the same facial features as FFDD2, but the inheritance is autosomal recessive. FFDD4 (614974) is characterized by isolated, preauricular skin lesions with autosomal dominant or recessive inheritance (summary by Slavotinek et al., 2013). Genetic Heterogeneity of Focal Facial Dermal Dysplasia FFDD3 (227260) is caused by mutation in the TWIST2 gene (607556) on chromosome 2q37. FFDD4 (614974) is caused by mutation in the CYP26C1 gene on chromosome 10q23. [from OMIM]

Any cleft lip/palate in which the cause of the disease is a mutation in the DLX4 gene. [from MONDO]

Neuroocular syndrome-1 (NOC1) encompasses a broad spectrum of overlapping anomalies, with developmental delay or impaired intellectual development as a consistent finding. Eye abnormalities show marked variability in the type and severity of defects, and include anophthalmia, microphthalmia, and coloboma. Other common systemic features include congenital heart and kidney defects, hypotonia, failure to thrive, and microcephaly (summary by Chowdhury et al., 2021). Genetic Heterogeneity of Neuroocular Syndrome See also NOC2 (168885), caused by mutation in the DAGLA gene (614015) on chromosome 11q12. [from OMIM]