Coffin-Siris Syndrome (CSS) is a genetic disorder which may be linked to a number of mutations in different genes. The diagnosis can be challenging when trying to identify the specific causative mutation.
Key features:
(1) abnormal distal phalanx of the fifth finger (hypoplastic nail. hypoplasia, aplasia)
(2) other disorders of the digits (additional digits, clinodactyly)
(3) variable developmental or cognitive delay with intellectual disability
(4) "coarse" facial dysmorphism (wide mouth, thick lips, broad nasal bridge, broad nasal tip, thick eyebrows, long eyelashes)
(5) hypotonia
(5) hirsutism and hypertrichosis
(6) sparse scalp hair, especially over the temporal region, with low anterior hairline
Additional findings may include:
(1) cardiac malformations
(2) gastrointestinal malformations
(3) renal and other genitourinary malformations
(4) microcephaly and malformations of the central nervous system (CNS)
(5) feeding difficulties
(6) slow growth
(7) visual impairment
(8) hearing impairment
(9) speech impairment
(10) seizures
(11) behavioral abnormalities (hyperactivity, autism, etc)
(12) dental abnormalities
(13) frequent infections
