A 15-day-old baby with Down syndrome, during routine blood testing found to have high leukocyte count (34,000), the baby otherwise is asymptomatic. Of the following, the MOST appropriate advice /action is

Correct Answer: D

Rationale: Transient leukemoid reaction in DS newborns is common and benign (D). Rationale: Resolves spontaneously; leukemia (A) is a risk but not at 15 days without symptoms.

Correct Answer: D

Rationale: Homeobox gene mutations are linked to developmental anomalies like hand-foot-uterus syndrome (HOXA13), hypodontia (PAX9), Waardenburg syndrome (PAX3), and pituitary hormone deficiency (PITX2). Type 1 diabetes is primarily autoimmune and not directly tied to homeobox mutations.

Correct Answer: D

Rationale: Y chromosome material in Turner syndrome (e.g., 45,X/46,XY mosaicism) increases gonadoblastoma risk, a potentially malignant tumor. This is the primary screening reason, not masculinization, contraception, androgen therapy, or prostate cancer (which requires a prostate).

Correct Answer: D

Rationale: Genomic similarity is higher within ethnic groups due to shared ancestry. Individual A (African) is more similar to another unaffected African than to Individual E (European), despite shared HL, which may have different genetic causes.

Correct Answer: D

Rationale: Exons (coding regions) have the lowest variation between humans (~0.1%) due to evolutionary conservation of protein function. Non-coding regions (repeats, introns, transposable elements) tolerate more variation.