Genetic and environmental factors contributing to anophthalmia and microphthalmia: Current understanding and future directions

Table 1 Common chromosomal abnormalities associated with anophthalmia and microphthalmia

Type of chromosomal abnormality	Chromosome abnormality	Other features
Aneuploidy	Trisomy 9 mosaicism	Joint contractures, congenital heart defects, prenatal growth deficiency, learning difficulties, micrognathia, kyphoscoliosis
	Trisomy 13 (patau syndrome)	Holoprosencephaly, moderate microcephaly, coloboma, retinal dysplasia, cyclopia, cleft lip/palate, cardiac defects, genital abnormalities, 86% die within one year
	Trisomy 18 (edwards syndrome)	Polyhydramnios, single umbilical artery, small placenta, low fetal activity, learning difficulties, hypertonicity, hypoplasia of skeletal muscle, subcutaneous, adipose tissue, prominent occiput, low-set malformed auricles, micrognathia, cardiac defects
Triploidy	Triploidy	Large placenta with hydatidiform changes, growth deficiency, syndactyly, congenital heart defects, brain anomalies/holoprosencephaly
Deletion	4p (wolf-hirschhorn syndrome)	Growth deficiency, microcephaly, ocular hypertelorism, cranial asymmetry, learning difficulties, epilepsy, cleft lip/palate, anterior segment dysgenesis
	Deletion 7p15.1-p21.1	Cryptophthalmos, cleft lip/palate, choanal atresia
	13q-, ring 13	Microcephaly, learning difficulties, bilateral retinoblastoma, cardiac defects, hypospadias, cryptorchidism
	Deletion 14q22.1-q23.2	Pituitary hypoplasia
	18q	Midface hypoplasia, small stature, learning difficulties, hypotonia, nystagmus, conductive deafness, microcephaly, midface hypoplasia, genital abnormalities
Duplication	3q syndrome (3q21-ter dup)	Learning difficulties, growth deficiency, hypertrichosis, craniosynostosis, cardiac defects, chest deformities, genital abnormalities, umbilical hernia
	4p syndrome	Learning difficulties, epilepsy, growth deficiency, obesity, microcephaly, characteristic faces, genital abnormalities, kyphoscoliosis
	10q syndrome	Ptosis, short palpebral fissures, camptodactyly, learning difficulties, prenatal growth deficiency, microcephaly, heart and kidney malformations