8 year-old male patient, complains short stature in a routine pediatric consultation. Analysis of Basic Unit papers reveals stature under Z-score = -2 on the WHO Child Growth Standards, pattern registered on previous consultations. Also presented an approximately 4cm growth in the last year. Weight standards and neuropsychomotor development are both adequate to his age. No other complaints. Father's stature: 168cm; mother's stature: 158cm. Physical examination within normality.

Question:
Considering the information provided and the radiography shown, one could say that this is, probably, a case of:

(Unicamp – Medical Residency - 2001) 14 year-old boy complains that he “doesn’t grow as his siblings”. Refers that has always been smaller than children at the same age, eats well and practices exercises. Denies other complaints or growth deceleration. No pregnancy nor birth complications. Birth weight = 2.300g and height = 47cm. Neuropsychomotor development within normality. Mother’s stature = 1,60m and father’s = 1,72. Mother’s menarche at 15 y.o. and father’s beard start to grow at 17 y.o. Body’s weight in the 15 percentile (45kg) and stature in the 3 percentile (1,50m), no alterations at physical examination. Brings left hand and fist radiography with bone age compatible with 11 y.o.

Question:
According to the available data, the most likely hypothesis about the patient’s complaint is: