Hair growth from a single point on the scalp in any location other than lateral to the midline and close to the vertex of the skull
Placement of hair whorl should be described as parietal, vertex, eccentric, etc. In addition, the number of hair whorls should be noted. Five percent of the population has two whorls.
Synonyms: Crown, Double
Hairline, Low Posterior
Definition: Hairline, Low Posterior
Subjective: Hair on the neck extends more inferiorly than usual
Comments:This feature is often seen in later childhood, as the neck lengthens, in an individual who was born with redundant nuchal skin, which should be assessed and coded separately.
Objective: Presence of a supernumerary digit that is not a hallux
Comments:Although it is appealing to believe in many cases that the supernumerary (non-hallux) digit is the most fibular, there may be no evidence for this. When the digit is de minimus, this seems reasonable by parsimony. When it is fully formed, associated with a supernumerary metatarsal, and fully functional, it may be impossible to determine which toe is supernumerary. Nevertheless, the designation as postaxial is reasonable given the tradition of this designation. Postaxial polydactyly has been divided into two types: A (a fully formed digit) and B (digitus minimus, or a pedunculated, non-articulating, non-functional appendage). We recognize these subtypes but note that post-axial polydactyly actually represents a spectrum from type A to type B. When the type is indeterminate, no subtype is specified. The term uses the word postaxial instead of the embryologic posterior because the former is established in clinical medicine.
Replaces: Posterior Duplication of the Limb/Foot, Fibular Polydactyly
A full-term infant was born with ambiguous genitalia (Panel A). There was no family history of similar presentations or known genetic disorders. The neonate was noted to have sinus tachycardia with a heart rate of up to 179 beats per minute without hypotension. Laboratory evaluation revealed an elevated potassium level of 7.4 mmol per liter (normal range for all persons, 3.5 to 5.3), a low sodium level of 125 mmol per liter (normal range, 135 to 148), an elevated 17-hydroxyprogesterone level of 196.0 μg per liter (593.0 nmol per liter; normal range, 0.5 to 2.4 μg per liter [1.5 to 7.0 nmol per liter]), and a testosterone level of more than 15.0 ng per milliliter (52.0 nmol per liter; normal range, 0.1 to 0.8 ng per milliliter [0.3 to 2.8 nmol per liter]). Ultrasonography of the abdomen revealed bilateral adrenal hypertrophy without visible testes, and chromosomal analysis revealed the 46 XX karyotype. Salt-losing congenital adrenal hyperplasia due to 21-hydroxylase deficiency in a female infant was diagnosed. The ambiguous genitalia, which is characterized by hypertrophy of the clitoris and labia majora and the presence of a urogenital sinus, may resemble hypospadias with cryptorchidism in males. Medical management of electrolyte abnormalities, intravenous fluids, and glucocorticoid and mineralocorticoid replacement were initiated. At 2 years of age, the patient underwent complex surgical reconstruction, including repair of the urogenital sinus (Panel B, black arrow), clitoroplasty (arrowhead), and vaginoplasty (white arrow). The patient has regular follow-up and is doing well with glucocorticoid and mineralocorticoid replacement therapy.